What type of resistor do I need?

[neverunwired@aol.com]

I'm upgrading the tail lamps on my vehicle and one set of bulbs are not
being used in the new configuration. However, these two bulbs were monitored
by the vehicle's bulb failure system.

I'd like to exchange the bulbs with two resistors (to trick the Bulb Failure
Module), but I'm not sure what kind to use.

They are 5 Watt bulbs.

Thanks
-John

 

[Rich Grise]

On Tue, 15 Feb 2005 00:45:39 +0000, neverunwired@aol.com wrote:

I'm upgrading the tail lamps on my vehicle and one set of bulbs are not
being used in the new configuration. However, these two bulbs were monitored
by the vehicle's bulb failure system.

I'd like to exchange the bulbs with two resistors (to trick the Bulb Failure
Module), but I'm not sure what kind to use.

They are 5 Watt bulbs.

If it's a 12V system, then each is drawing P = I * E; I = P / E: 5/12 =
..417 amp. So the resistance is, lessee R = E / I = 12/.417 28.8 ohms.
So 27 or 30 ohms, 10 watts. You could use 5 watt resistors, but they'd be
at their max. rating.

Good Luck!
Rich

 

[neverunwired@aol.com]

The system only detects bulb failure when the lights are on. And the newer
unit does not allow clearance for this particular bulb.
"Anthony Fremont" <spam@anywhere.com> wrote in message
newsgcQd.58070$sr1.7090@fe2.texas.rr.com...

"neverunwired@aol.com" <johnandhan@verizon.net> wrote in message
news:TCbQd.7072$uc.3273@trnddc01...
I'm upgrading the tail lamps on my vehicle and one set of bulbs are
not
being used in the new configuration. However, these two bulbs were
monitored
by the vehicle's bulb failure system.

I'd like to exchange the bulbs with two resistors (to trick the Bulb
Failure
Module), but I'm not sure what kind to use.

They are 5 Watt bulbs.

It may not be that simple. Light bulbs have a much lower resistance
when they are off than they do when they get hot. Depending upon the
method of detecting bulb failures, the circuit may rely on the off
resistance (which is what I suspect) or it may detect the high current
flowing thru the wire when it's on (I doubt it). At any rate, you will
need rather large (physically) resistors to dissipate the power (like
10W to be safe). 33 Ohms would be close to the on resistance of a bulb.
When the bulb is off, it's likely to be about 1-3 Ohms.

I would be inclined to leave the bulbs wired into their circuits and
paint them black.

 

[legg]

On Tue, 15 Feb 2005 02:29:26 GMT, "neverunwired@aol.com"
<johnandhan@verizon.net> wrote:

To possibly clarify something...I know that on the vehicle, the 55W fog
lights (optional), if not fitted, were replaced with a 1000 ohm (don't know
the wattage rating, etc.) resistor to override the bulb failure system. I'm
trying to apply the same concept, but I don't know the appropriately rating
of resistor needed for a 5W bulb. Obviously I need just enough current
bridged to make the module think a bulb is in place.

Don't know if that tells you how 'sensitive' the BFM is or if it makes any
difference. Not very educated in this area, just pick a little
up along the way.
"neverunwired@aol.com" <johnandhan@verizon.net> wrote in message
news:TCbQd.7072$uc.3273@trnddc01...

Sounds like the bulb detector is using the lamp's presence as a
pull-up or pull down, when unpowered, to detect continuity vs open or
blown fuse.

1K should work in the second case also, regardless of power, if so.

RL

 

[Rich Webb]

On Tue, 15 Feb 2005 03:58:50 -0600, "Brian" <brian@w3gate.com> wrote:

And when you do this, some weinerhead will tell you not to crosspost

True enough. It's almost always better to be familiar enough with the
newsgroup to know that the post is on-topic and post to that single
group.

Of course, if a weinerhead does complain that crossposting is worse than
multiposting, there's always that other handy usenet tradition of adding
the w.h. to the "improve my signal-to-noise ratio" file... ;-)

[Traditionally, follow-ups to this posting should either point out
grammatical and spelling errors or note that it's not on topic.]

--
Rich Webb Norfolk, VA

 

[neverunwired@aol.com]

I've tried many of the combinations suggested by everyone, but I'm afraid
I've been unable to fool the BFM with a resistor(s). I was, however, able to
wire and conceal a small 'dim' 5W bulb into the circuit...looks and works
fine. Thanks for everyone's expertise!
-John
"neverunwired@aol.com" <johnandhan@verizon.net> wrote in message
news:TCbQd.7072$uc.3273@trnddc01...

I'm upgrading the tail lamps on my vehicle and one set of bulbs are not
being used in the new configuration. However, these two bulbs were
monitored by the vehicle's bulb failure system.

I'd like to exchange the bulbs with two resistors (to trick the Bulb
Failure Module), but I'm not sure what kind to use.

They are 5 Watt bulbs.

Thanks
-John

 

[Rich Grise]

On Tue, 15 Feb 2005 22:19:26 +0000, Rich Webb wrote:

On Tue, 15 Feb 2005 03:58:50 -0600, "Brian" <brian@w3gate.com> wrote:


And when you do this, some weinerhead will tell you not to crosspost

True enough. It's almost always better to be familiar enough with the
newsgroup to know that the post is on-topic and post to that single
group.

Of course, if a weinerhead does complain that crossposting is worse than
multiposting, there's always that other handy usenet tradition of adding
the w.h. to the "improve my signal-to-noise ratio" file... ;-)

[Traditionally, follow-ups to this posting should either point out
grammatical and spelling errors or note that it's not on topic.]

Or, just to point out that usually the ones who bitch about crossposting
crosspost their bitch. ;-)

Cheers!
Rich