The Stovebolt Site Forums The Shop Area The Electrical Bay Electrical leak?

In my not too well lit garage I can see a faint spark when I connect the positive terminal of the battery. Is this normal or do I have an electrical leak somewhere. If it's the latter I'm in real trouble because I have done so many things in the wiring I wouldn't know where to start. Your thoughts please.

Thanks, Don

Do you have any device that has a memory -- ECM or perhaps a radio? If not and the interior lighs are out then I would think you have an electrical drain. You might be able to make a swag by measuring the current draw -- though more than likely it will just be a case of elimenating circuits/devices one at a time.

If there is nothing connected, the ignition is not on, there should be no spark at all. You do have something that is drawing current.

Try pulling the fuses one by one to isolate the draw (Leak). Then go from there.

If you have an alternator, depending on how it's wired, you can get a slight current through the internal regulator when the engine is shut off. On a daily driver it's not a problem, but on a "toy" that might sit for months without being started, it can eventually drain the battery. I pull the plug on the alternator on my toys when they aren't in regular use(winter).

I put a diode on my ignition wire ... it stops the voltage from going back towards the ignition and eliminates engine "run-on" -- maybe that would do it?

See Here

Thanks to all for their advice/suggestions. The truck has been re-wired and changed over to 12V with an alternator. Since I do not know how to verify whether or not it's the alternator causing the leakage I will pull fuses, one at a time and see if I come up with the solution. Alan, I have not checked your diode installation but will do so shortly and see if it's something I can do.

Thanks again, Don

Be aware that though popular the diode solution does have a down side.

There is about a 1/2-volt drop across the diode, and this means the alternator is not correctly reading the battery's charge.

As a result you could have some battery issues. I'd not expect it to be a problem if you don't drive the truck much. If you use the truck frequently I'd expect it to decrease battery life because the battery is always being over-charged.