case grounded motor wiring

[Pat Kilgore]

I am wiring a car windshield wiper motor directly to a car battery. The
wiring diagram says +12v Terminal1 -12v case grounded
Does that mean to connect positive lead to terminal one and the negative
lead from the battery is made to contact the case, probably at the
mounting bolt?
I realized that is probably as basic a question as it gets, but if you
don't know?

Thanks
Pat

 

[John Popelish]

Pat Kilgore wrote:

I am wiring a car windshield wiper motor directly to a car battery. The
wiring diagram says +12v Terminal1 -12v case grounded
Does that mean to connect positive lead to terminal one and the negative
lead from the battery is made to contact the case, probably at the
mounting bolt?
I realized that is probably as basic a question as it gets, but if you
don't know?

Thanks
Pat
It means that there is one obvious terminal and that one goes to the

positive side of the battery. The case connects to the negative side
of the battery. In other words, it is designed for a negative (side
of the battery connected to) ground system.

 

[Pat Kilgore]

John Popelish wrote:

Pat Kilgore wrote:

I am wiring a car windshield wiper motor directly to a car battery.
The wiring diagram says +12v Terminal1 -12v case grounded
Does that mean to connect positive lead to terminal one and the
negative lead from the battery is made to contact the case, probably
at the mounting bolt?
I realized that is probably as basic a question as it gets, but if you
don't know?

Thanks
Pat

It means that there is one obvious terminal and that one goes to the
positive side of the battery. The case connects to the negative side of
the battery. In other words, it is designed for a negative (side of the
battery connected to) ground system.
Thanks. Works like a charm. Now I'm curious why you don't toast

yourself, or at least get a thrill when you grab the engine block.

 

[Jonathan Westhues]

"Pat Kilgore" <palito@earthlink.net> wrote in message
news_Sge.1544$bm5.1157@newsread3.news.atl.earthlink.net...

Thanks. Works like a charm. Now I'm curious why you don't toast
yourself, or at least get a thrill when you grab the engine block.

A1: You don't complete the circuit. In order for any current to flow you
need to touch both terminals of the battery, and when you touch the engine
block you are only connected to one of them.

A2: 12V is too little to feel anyways, unless you stick it on your tongue.
Though you could do some arc welding if you put a screwdriver across the
terminals (because a very high current is available).

Jonathan

 

Pat Kilgore wrote:

Thanks. Works like a charm. Now I'm curious why you don't toast
yourself, or at least get a thrill when you grab the engine block.

You need to be touching two different potentials with the difference
large enough to drive at least a milliamp or more through you before
you feel a shock. Dry skin resistance is normally in the 10s of
thoudsands of ohms. 12 volts can't push enough current through that to
be above the threshold of sensation. Most people start to feel a
tingle somewhere between 40 and 70 volts across dry skin. Your tongue
requires much less. If you puncture the skin (or it is wet, especially
with salt water), much less is needed for a shock.