Alternator Output Drops Above 45 C After 75 km

[Bret Cahill]

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must be some thresh hold where the rectifier or voltage regulator is really sensitive to even small changes in temps.


Bret Cahill

 

[rickman]

Bret Cahill wrote on 7/19/2017 12:15 PM:

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must be some thresh hold where the rectifier or voltage regulator is really sensitive to even small changes in temps.

Does this only happen during the day and not at night? What is the voltage
on the system when you start running and when the engine fails, also with
and without lights? I'm not sure how you can restart the engine if the
voltage is so low the engine won't run. I'm thinking it is an issue with
the engine control computer rather than the electrical system.

You can get voltmeters off eBay that plug into your lighter socket.

--

Rick C

 

[Bret Cahill]

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must be some thresh hold where the rectifier or voltage regulator is really sensitive to even small changes in temps.

Does this only happen during the day and not at night?

I avoid driving at night when it's really hot.

LED headlights would solve the problem and are actually cheaper than voltage regulators if you can believe that.

What is the voltage
on the system when you start running and when the engine fails,

I'll check it out.

also with
and without lights? I'm not sure how you can restart the engine if the
voltage is so low the engine won't run.

The battery restarts the engine just fine. Autozone tested it claiming everything is A-OK with the charging system. Of course, the engine had been off for a couple of minutes so that test wasn't too useful.

I'm thinking it is an issue with
the engine control computer rather than the electrical system.

I should have thought of that.

> You can get voltmeters off eBay that plug into your lighter socket.

I'll wire up a plug to a multi meter next trip into the heat. I should have thought of that too. Thanks again.

You can conceptualize w/o language but you cannot think w/o language.


Bret Cahill

 

[rickman]

Bret Cahill wrote on 7/19/2017 2:43 PM:

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must be some thresh hold where the rectifier or voltage regulator is really sensitive to even small changes in temps.

Does this only happen during the day and not at night?

I avoid driving at night when it's really hot.

I'm trying to figure out if it *is* the heat. Heck, it could be something
blocking the exhaust or something with the fuel supply.


> LED headlights would solve the problem and are actually cheaper than voltage regulators if you can believe that.

How do you know LED headlights will solve the problem if you don't know what
the problem is?

What is the voltage
on the system when you start running and when the engine fails,

I'll check it out.

also with
and without lights? I'm not sure how you can restart the engine if the
voltage is so low the engine won't run.

The battery restarts the engine just fine. Autozone tested it claiming everything is A-OK with the charging system. Of course, the engine had been off for a couple of minutes so that test wasn't too useful.

If your alternator stops working because of the heat, the battery will run
down. The system voltage can't droop without the battery loosing charge.
So if the engine starts ok something else is wrong.

Do the headlights dim? That's an indication of low voltage to the headlights.

I'm thinking it is an issue with
the engine control computer rather than the electrical system.

I should have thought of that.

You can get voltmeters off eBay that plug into your lighter socket.

I'll wire up a plug to a multi meter next trip into the heat. I should have thought of that too. Thanks again.

You can conceptualize w/o language but you cannot think w/o language.

It can also be something as mundane as the ignition coil. Do you have one
or several? If one it could be that. Or if you have an ignition resistor
that can be opening in the heat. The symptom will be the engine starts
while you turn the key to start, but as soon as you release it to ON, the
engine dies.

--

Rick C

 

[Bret Cahill]

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must be some thresh hold where the rectifier or voltage regulator is really sensitive to even small changes in temps.

Does this only happen during the day and not at night?

I avoid driving at night when it's really hot.

I'm trying to figure out if it *is* the heat.

This never happens below 40 C so heat is definitely one leg of the 2 legged stool.

Heck, it could be something
blocking the exhaust or something with the fuel supply.

I always think it's a clogged fuel filter at first. Later down the road I remember trying changing the filter so this issue is not a clogged fuel filter.

Maybe the fuel pump creates enough of a vacuum so that the pressure drops below vapor pressure which should be quite high at 50 - 60C. Then the pump could lose suction. The problem with that theory is the fuel system should not be affected by a load on the electrical system, especially a cam driven fuel pump.

LED headlights would solve the problem and are actually cheaper than voltage regulators if you can believe that.

How do you know LED headlights will solve the problem if you don't know what
the problem is?

Halogens draw a lot of power which hastens the onset / aggravates the mis firing enormously but _only when it is really hot_.

What is the voltage
on the system when you start running and when the engine fails,

I'll check it out.

also with
and without lights? I'm not sure how you can restart the engine if the
voltage is so low the engine won't run.

The battery restarts the engine just fine. Autozone tested it claiming everything is A-OK with the charging system. Of course, the engine had been off for a couple of minutes so that test wasn't too useful.

If your alternator stops working because of the heat, the battery will run
down. The system voltage can't droop without the battery loosing charge.
So if the engine starts ok something else is wrong.

The distributor ignition module is a suspect component. Maybe a combination of heat + a load on the electrical system for a slightly different voltage is too much for it.

There isn't any easy way to dismiss that theory.

> Do the headlights dim? That's an indication of low voltage to the headlights.

I don't remember ever having dim lights.

I'm thinking it is an issue with
the engine control computer rather than the electrical system.

I should have thought of that.

You can get voltmeters off eBay that plug into your lighter socket.

I'll wire up a plug to a multi meter next trip into the heat. I should have thought of that too. Thanks again.

You can conceptualize w/o language but you cannot think w/o language.

It can also be something as mundane as the ignition coil. Do you have one
or several?

One. The resistances check out OK at lower temperatures. Maybe something opens up in the heat.

If one it could be that. Or if you have an ignition resistor
that can be opening in the heat. The symptom will be the engine starts
while you turn the key to start, but as soon as you release it to ON, the
engine dies.

It'll start immediately and stay running until there's some combination of too much electrical load + too much heat.


Bret Cahill

 

[rickman]

Bret Cahill wrote on 7/19/2017 8:49 PM:

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must be some thresh hold where the rectifier or voltage regulator is really sensitive to even small changes in temps.

Does this only happen during the day and not at night?

I avoid driving at night when it's really hot.

I'm trying to figure out if it *is* the heat.

This never happens below 40 C so heat is definitely one leg of the 2 legged stool.

Heck, it could be something
blocking the exhaust or something with the fuel supply.

I always think it's a clogged fuel filter at first. Later down the road I remember trying changing the filter so this issue is not a clogged fuel filter.

Maybe the fuel pump creates enough of a vacuum so that the pressure drops below vapor pressure which should be quite high at 50 - 60C. Then the pump could lose suction. The problem with that theory is the fuel system should not be affected by a load on the electrical system, especially a cam driven fuel pump.

LED headlights would solve the problem and are actually cheaper than voltage regulators if you can believe that.

How do you know LED headlights will solve the problem if you don't know what
the problem is?

Halogens draw a lot of power which hastens the onset / aggravates the mis firing enormously but _only when it is really hot_.

What is the voltage
on the system when you start running and when the engine fails,

I'll check it out.

also with
and without lights? I'm not sure how you can restart the engine if the
voltage is so low the engine won't run.

The battery restarts the engine just fine. Autozone tested it claiming everything is A-OK with the charging system. Of course, the engine had been off for a couple of minutes so that test wasn't too useful.

If your alternator stops working because of the heat, the battery will run
down. The system voltage can't droop without the battery loosing charge.
So if the engine starts ok something else is wrong.

The distributor ignition module is a suspect component. Maybe a combination of heat + a load on the electrical system for a slightly different voltage is too much for it.

There isn't any easy way to dismiss that theory.

Sure there are lots of ways. Try taking some measurements.

Do the headlights dim? That's an indication of low voltage to the headlights.

I don't remember ever having dim lights.

Then there is nothing wrong with the voltage. Forget the alternator,
regulator and system voltage.

I'm thinking it is an issue with
the engine control computer rather than the electrical system.

I should have thought of that.

You can get voltmeters off eBay that plug into your lighter socket.

I'll wire up a plug to a multi meter next trip into the heat. I should have thought of that too. Thanks again.

You can conceptualize w/o language but you cannot think w/o language.

It can also be something as mundane as the ignition coil. Do you have one
or several?

One. The resistances check out OK at lower temperatures. Maybe something opens up in the heat.

Duh, that's the point. It can be opening up at high temps. Same with the
resistor.

If one it could be that. Or if you have an ignition resistor
that can be opening in the heat. The symptom will be the engine starts
while you turn the key to start, but as soon as you release it to ON, the
engine dies.

It'll start immediately and stay running until there's some combination of too much electrical load + too much heat.

I'm talking about after it fails and won't run. Above you said you have to
wait 2 minutes until it will start. You need to check things *then*. No
point in checking them when they are working.

Does the engine stumble, lose power and die or just quit like you turned it
off?

--

Rick C

 

[default]

On Wed, 19 Jul 2017 09:15:14 -0700 (PDT), Bret Cahill
<bretcahill@aol.com> wrote:

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must be some thresh hold where the rectifier or voltage regulator is really sensitive to even small changes in temps.


Bret Cahill

99% of the time alternator problems are caused by brushes. First
suspect with any vehicle that has 50K+ miles on it. (although some new
alternators don't have brushes... and some go for 200K before they
wear enough)

Warm temps can cause the metal in the holders or the insulating
material to expand causing the brushes to bind in the slip ways. If
the brushes are at the end of their life, the small amount of run-out
(wobble) can kick the brushes up into the slip holders where they stay
until it cools enough so the spring can push it back into contact with
the rings.

How many miles on the car?

Brushes are cheap - ~$4 ($8 in NY to fix my OM's car) take it to a
garage and they replace the alternator for $300, or claim they rewound
the rotor for about that same amount.

Pressed in diodes on the alternator housing can also cause that, if
they are rusted between the diode case (steel) and aluminum
alternator.

 

[Jim Thompson]

How about replacing it with a 140A alternator...

<https://www.amazon.com/ALTERNATOR-PETERBILT-19011187-19011258-321-758/dp/B008BB4OOS>:-}

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I'm looking for work... see my website.

Thinking outside the box...producing elegant & economic solutions.

 

[rickman]

default wrote on 7/20/2017 6:18 AM:

On Wed, 19 Jul 2017 09:15:14 -0700 (PDT), Bret Cahill
bretcahill@aol.com> wrote:

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must be some thresh hold where the rectifier or voltage regulator is really sensitive to even small changes in temps.


Bret Cahill

99% of the time alternator problems are caused by brushes. First
suspect with any vehicle that has 50K+ miles on it. (although some new
alternators don't have brushes... and some go for 200K before they
wear enough)

Warm temps can cause the metal in the holders or the insulating
material to expand causing the brushes to bind in the slip ways. If
the brushes are at the end of their life, the small amount of run-out
(wobble) can kick the brushes up into the slip holders where they stay
until it cools enough so the spring can push it back into contact with
the rings.

How many miles on the car?

Brushes are cheap - ~$4 ($8 in NY to fix my OM's car) take it to a
garage and they replace the alternator for $300, or claim they rewound
the rotor for about that same amount.

Pressed in diodes on the alternator housing can also cause that, if
they are rusted between the diode case (steel) and aluminum
alternator.

There is nothing wrong with his alternator. He has not measured anything to
show there *is* a problem. His engine stops running when it is hot out and
he jumped to a conclusion that it had to be an alternator problem. At this
point he has reported no measurements that would support the idea that the
problem is the charging system. He has said the light do not dim and the
engine starts fine after things sit for a couple of minutes, so I don't see
how it can be the charging system.

--

Rick C

 

On Wednesday, July 19, 2017 at 12:15:18 PM UTC-4, Bret Cahill wrote:

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must be some thresh hold where the rectifier or voltage regulator is really sensitive to even small changes in temps.


Bret Cahill

I had the same problem. I would squirt some Cold Spray onto the fuel pump and away we go... Vapor lock? Bad vent on gas cap?

 

[Rheilly Phoull]

On 21/07/2017 4:25 AM, rickman wrote:

default wrote on 7/20/2017 6:18 AM:
On Wed, 19 Jul 2017 09:15:14 -0700 (PDT), Bret Cahill
bretcahill@aol.com> wrote:

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible
_without lights_.

It's hard to imagine anything cooling off in just 2 minutes. There
must be some thresh hold where the rectifier or voltage regulator is
really sensitive to even small changes in temps.


Bret Cahill

99% of the time alternator problems are caused by brushes. First
suspect with any vehicle that has 50K+ miles on it. (although some new
alternators don't have brushes... and some go for 200K before they
wear enough)

Warm temps can cause the metal in the holders or the insulating
material to expand causing the brushes to bind in the slip ways. If
the brushes are at the end of their life, the small amount of run-out
(wobble) can kick the brushes up into the slip holders where they stay
until it cools enough so the spring can push it back into contact with
the rings.

How many miles on the car?

Brushes are cheap - ~$4 ($8 in NY to fix my OM's car) take it to a
garage and they replace the alternator for $300, or claim they rewound
the rotor for about that same amount.

Pressed in diodes on the alternator housing can also cause that, if
they are rusted between the diode case (steel) and aluminum
alternator.

There is nothing wrong with his alternator. He has not measured
anything to show there *is* a problem. His engine stops running when it
is hot out and he jumped to a conclusion that it had to be an alternator
problem. At this point he has reported no measurements that would
support the idea that the problem is the charging system. He has said
the light do not dim and the engine starts fine after things sit for a
couple of minutes, so I don't see how it can be the charging system.

+1

 

[Ian Field]

"Bret Cahill" <bretcahill@aol.com> wrote in message
news:88ea49c2-e03a-435e-9d03-d579a7cedf1b@googlegroups.com...

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without
lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must
be some thresh hold where the rectifier or voltage regulator is really
sensitive to even small changes in temps.

Apparently the exact terminal voltage has to be set according to
temperature - I assume there's a circuit in there somewhere with a
thermistor.

AFAICR: there's appnotes about this on Jim Thompson's website - analogue
solutions or something.

 

[Ian Field]

"default" <default@defaulter.net> wrote in message
news:k401nc5c4n20p4epijn5oejvv65n508575@4ax.com...

On Wed, 19 Jul 2017 09:15:14 -0700 (PDT), Bret Cahill
bretcahill@aol.com> wrote:

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without
lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must
be some thresh hold where the rectifier or voltage regulator is really
sensitive to even small changes in temps.


Bret Cahill

99% of the time alternator problems are caused by brushes. First
suspect with any vehicle that has 50K+ miles on it. (although some new
alternators don't have brushes... and some go for 200K before they
wear enough)

Slip ring brushes last a lot longer on field rotor alternators - I've only
seen them on motorcycles, but the latest thing is interleaved poles only
rotor coupled to the field assembly via a coaxial pole arrangement. No
brushes at all.

 

[Ian Field]

"rickman" <gnuarm@gmail.com> wrote in message
newskr3bj$qci$1@dont-email.me...

default wrote on 7/20/2017 6:18 AM:
On Wed, 19 Jul 2017 09:15:14 -0700 (PDT), Bret Cahill
bretcahill@aol.com> wrote:

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without
lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must
be some thresh hold where the rectifier or voltage regulator is really
sensitive to even small changes in temps.


Bret Cahill

99% of the time alternator problems are caused by brushes. First
suspect with any vehicle that has 50K+ miles on it. (although some new
alternators don't have brushes... and some go for 200K before they
wear enough)

Warm temps can cause the metal in the holders or the insulating
material to expand causing the brushes to bind in the slip ways. If
the brushes are at the end of their life, the small amount of run-out
(wobble) can kick the brushes up into the slip holders where they stay
until it cools enough so the spring can push it back into contact with
the rings.

How many miles on the car?

Brushes are cheap - ~$4 ($8 in NY to fix my OM's car) take it to a
garage and they replace the alternator for $300, or claim they rewound
the rotor for about that same amount.

Pressed in diodes on the alternator housing can also cause that, if
they are rusted between the diode case (steel) and aluminum
alternator.

There is nothing wrong with his alternator. He has not measured anything
to show there *is* a problem. His engine stops running when it is hot out
and

Last time I had that was the middle HT lead to the distributor had a spark
eroded copper core - trim it back to make a proper connection and it worked
fine.

 

[Ian Field]

<sdeyoreo@hotmail.com> wrote in message
news:ed546d01-f90b-48ce-a748-dc3cc4bd7051@googlegroups.com...

On Wednesday, July 19, 2017 at 12:15:18 PM UTC-4, Bret Cahill wrote:
After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without
lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must
be some thresh hold where the rectifier or voltage regulator is really
sensitive to even small changes in temps.


Bret Cahill

I had the same problem. I would squirt some Cold Spray onto the fuel pump
and away we go... Vapor lock? Bad vent on gas cap?

Some of the motorcycles I had - you could hear the vent whistling!

 

[M Philbrook]

In article <qFtcB.333494$YS2.257040@fx11.am4>, gangprobing.alien1
@virginmedia.com says...

"Bret Cahill" <bretcahill@aol.com> wrote in message
news:88ea49c2-e03a-435e-9d03-d579a7cedf1b@googlegroups.com...
After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without
lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must
be some thresh hold where the rectifier or voltage regulator is really
sensitive to even small changes in temps.

Apparently the exact terminal voltage has to be set according to
temperature - I assume there's a circuit in there somewhere with a
thermistor.

AFAICR: there's appnotes about this on Jim Thompson's website - analogue
solutions or something.

More like battery management sensing an over heated battery and dropping
back the charging voltage..

The module is normally mount under and very close to the battery
compartment..

Missing guards and rust in areas no longer blocking hot air from
hitting the compartment area could be heatnig up the module and giving
it a false sense.

Or, it just could be bad!

Jmaie

 

[default]

On Fri, 21 Jul 2017 21:45:27 +0100, "Ian Field"
<gangprobing.alien1@virginmedia.com> wrote:

"default" <default@defaulter.net> wrote in message
news:k401nc5c4n20p4epijn5oejvv65n508575@4ax.com...
On Wed, 19 Jul 2017 09:15:14 -0700 (PDT), Bret Cahill
bretcahill@aol.com> wrote:

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without
lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must
be some thresh hold where the rectifier or voltage regulator is really
sensitive to even small changes in temps.


Bret Cahill

99% of the time alternator problems are caused by brushes. First
suspect with any vehicle that has 50K+ miles on it. (although some new
alternators don't have brushes... and some go for 200K before they
wear enough)

Slip ring brushes last a lot longer on field rotor alternators - I've only
seen them on motorcycles, but the latest thing is interleaved poles only
rotor coupled to the field assembly via a coaxial pole arrangement. No
brushes at all.

If it is an older high-mileage vehicle it probably still has brushes.
My 91 Dodge Pickup does...

Town I lived in some years ago had this place that specialized in
alternator repairs. I'd hear people at work talking about their car
problems and mention the alternator place. If they are to be believed
rotors frequently require "rewinding," a $300 service. (in the 80's)

I later fixed a friend's car that he'd gotten an estimate for a "bad
rotor," and only had to replace the brushes.

I rewound one rotor my old Honda motorcycle. Rotor failure is rare -
most vehicles use the slight current from the alternator indicator
light or a resistor to excite the thing to get it charging, but when
it starts working a separate set of small diodes (3) on the positive
output side of the alternator supplies the exciting current - that way
a failure in the alternator doesn't cause the battery to discharge
through the rotor if the alternator has no output.

Motorcycles have it rough. The alternator is directly driven from the
crank shaft so all the heat of the (usually) air cooled engine is
present in the alternator and there are no fans to aid cooling just
the air the rotor stirs up to distribute heat. Modern bikes
frequently have PM alternators with the field on the outside of the
coils.

 

[Ian Field]

"default" <default@defaulter.net> wrote in message
news:kp86nc9htovkcj3ubh1ige22dt5bhd77di@4ax.com...

On Fri, 21 Jul 2017 21:45:27 +0100, "Ian Field"
gangprobing.alien1@virginmedia.com> wrote:



"default" <default@defaulter.net> wrote in message
news:k401nc5c4n20p4epijn5oejvv65n508575@4ax.com...
On Wed, 19 Jul 2017 09:15:14 -0700 (PDT), Bret Cahill
bretcahill@aol.com> wrote:

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without
lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must
be some thresh hold where the rectifier or voltage regulator is really
sensitive to even small changes in temps.


Bret Cahill

99% of the time alternator problems are caused by brushes. First
suspect with any vehicle that has 50K+ miles on it. (although some new
alternators don't have brushes... and some go for 200K before they
wear enough)

Slip ring brushes last a lot longer on field rotor alternators - I've only
seen them on motorcycles, but the latest thing is interleaved poles only
rotor coupled to the field assembly via a coaxial pole arrangement. No
brushes at all.

If it is an older high-mileage vehicle it probably still has brushes.
My 91 Dodge Pickup does...

Town I lived in some years ago had this place that specialized in
alternator repairs. I'd hear people at work talking about their car
problems and mention the alternator place. If they are to be believed
rotors frequently require "rewinding," a $300 service. (in the 80's)

I later fixed a friend's car that he'd gotten an estimate for a "bad
rotor," and only had to replace the brushes.

Assuming you catch it before they break up and rip up the commutator.

Almost a frequent occurrence in power tools.

 

[Tim Wescott]

On Wed, 19 Jul 2017 09:15:14 -0700, Bret Cahill wrote:

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without
lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must
be some thresh hold where the rectifier or voltage regulator is really
sensitive to even small changes in temps.

Y'know, the cool thing about experienced mechanics is that they see these
things ALL THE TIME, and while they may not have the foggiest notion of
the theory behind the problems, and they may even be dead wrong about the
"why" part of it, they usually have a pretty damned good idea of what
parts to fix/change/bang on to make the problem go away.

So why ask on an electronics group?

AFAIK generators have been failing at hot since well before there were
any semiconductors in the loop -- maybe it's just some grotty old
electromechanical problem, like the heat making the brushes get slack on
the slip rings, or something equally mundane.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[Jim Thompson]

On Sat, 22 Jul 2017 16:34:58 -0500, Tim Wescott
<seemywebsite@myfooter.really> wrote:

On Wed, 19 Jul 2017 09:15:14 -0700, Bret Cahill wrote:

After 50 - 75 km driving the ignition system starts to fail.

Pull over and wait 2 minutes and then another 50 km is possible _without
lights_.

It's hard to imagine anything cooling off in just 2 minutes. There must
be some thresh hold where the rectifier or voltage regulator is really
sensitive to even small changes in temps.

Y'know, the cool thing about experienced mechanics is that they see these
things ALL THE TIME, and while they may not have the foggiest notion of
the theory behind the problems, and they may even be dead wrong about the
"why" part of it, they usually have a pretty damned good idea of what
parts to fix/change/bang on to make the problem go away.

So why ask on an electronics group?

AFAIK generators have been failing at hot since well before there were
any semiconductors in the loop -- maybe it's just some grotty old
electromechanical problem, like the heat making the brushes get slack on
the slip rings, or something equally mundane.

I'm with you, Tim! I've never seen such a lengthy thread about
something that should have been resolved in a few days ;-)

...Jim Thompson
--
| James E.Thompson | mens |
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| Voice480)460-2350 Fax: Available upon request | Brass Rat |
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