Thread: Battery or Alternator bad?

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Nope, I'm not goonin ya! Ok, the test light your using, is it an incandescent bulb? ( Can't use an LED type for this type of test. )Did you have the door open at the time of the test? That would cause a draw, because the interior light would be on. How about the hood, have a light that comes on when it's open, or the trunk lid, same thing would happen. Everything has to be off, that would normally be off, including the key switch. Any of these would cause a closed circuit and make your test light come on. The one thing that may be getting you, is the plug on the alt that plugs into the regulator. Unplug it, to eliminate it, while you do your test. If everything is off, and pulling the fuses won't make the light go out, you have one of three things happening. 1. The circuit that is involved isn't fused, or 2. you have a short on the positive side somewhere, ( pinched or wire rubbed bare ) or 3. an item isn't being shut off with the key switch. ( Electric fuel pump? Stuck brake light switch? Glove box light? Radio-tape-CD player? ) With the test light hooked up inline ( in series ) on the positive cable, any, and all power flow will have to go through it. It will only light up if there is flow. Just have to keep hunting, feel and smell for anything getting hot. Now isn't being a mechanic fun. I've been doing this stuff for a lot of years, and most times these things are simple and stupid. Well, they are once you find them. Sniper