750mV from battery to ground, Tracing the short: any usual suspects? Options

[Prospectfarms]

Key off. Red terminal to body gives somewhere between 1V and 750mV. (IMG:style_emoticons/default/sad.gif) To me that seems like a bare wire short to ground but I'm not an expert.

Likely spots? Anyplace I could test first before tracing the whole electrical system?

How about a short (N.P.I.) list of always-hot wires in the car. Doesn't have to be comprehensive -- just looking for a starting point.

Thanks.

[stugray]

What?

Does the car run?
You should have ~12-13 Volts between the Positive terminal and the car chassis regardless of the switch position.
Same as between the + and - of the battery itself.

To find a short, you need to have the meter in series with the battery and measuring current not voltage.

Stu

[Prospectfarms]

What?

Does the car run?
You should have ~12-13 Volts between the Positive terminal and the car chassis regardless of the switch position.
Same as between the + and - of the battery itself.

To find a short, you need to have the meter in series with the battery and measuring current not voltage.

Stu

Thanks, Car runs. With the key off and the + terminal removed from the battery. I get a little less than 1V. between the positive clamp and positive battery post.

[ape914]

What?

Does the car run?
You should have ~12-13 Volts between the Positive terminal and the car chassis regardless of the switch position.
Same as between the + and - of the battery itself.

To find a short, you need to have the meter in series with the battery and measuring current not voltage.

Stu

Thanks, Car runs. With the key off and the + terminal removed from the battery. I get a little less than 1V. between the positive clamp and positive battery post.

the one volt drop is between the battery post and the batter clamp? that is telling me that you have a high resistance clamp. remove the clamp and clean it and the post, re-install and see if the voltage drop goes away. the drop on that connection should be near zero.

The next thing to ask is what is draining the current when every thing is supposed to be off. but for sure if you have a 1 volt drop across the clamp, you got a high resistance clamp / post connection and since this is happening with all accessories off, you got some current draw that should not be happening.

Fix the post / clamp issue first, then figure which of the positive terminal wires has the leakage, by hooking up each of the wires that go to the positive post one at a time , one of them has a leakage thru it, else you wouldn't see any drop across the clamp/post. So you really have two issues to deal with.