View Full Version : Battery Drain

05-24-05, 01:41 AM
I have a 1985 Fleetwood Brougham RWD. One day my theft deterrent system quit working, it just will not arm when I lock the doors. Now the security light on the dashboard flashes contantly. There's also about a 10 amp draw on the battery with everything off and the key out. Naturally, I have to keep charging my battery after a couple of days.

Does anyone know where the theft deterrent module is located so I can replace it or fix it?

05-24-05, 02:12 AM
10 AMP draw??? WOW! That is a LOT. I would start pulling fuses 1 by 1 till I find it.

That should be easy, not to mention, that is also a lot of heat.

Is the fuel pump still running? The Theft module is located above the gas pedal/brake pedal. There is 2 inline fuses in the theft ckt. You might try removing them one at a time to see which is guilty of the power drain. I have an FSM if you need help, althought it doens't look very helpful.

05-25-05, 11:52 AM
Thanks for the hint, now I know the general location. I've already removed every fuse on the block with no luck, so I suspect it's the theft deterrent system or some other device that gets it's power directly from the battery.

05-25-05, 12:27 PM
Alternator? That will do it too, I had a bad diode in the bridge recifier that did weird things all over the car and was draining the battery. Pull the big wire to the alt and see if it goes away.

You can have it tested. Alternators are cheap to rebuild on any early 70's to 96 RWD Cadillac.

The Ape Man
05-25-05, 09:21 PM
10 Amperes is a lot of draw. Something should be making some heat. I'd suspect the rectifier diodes in the alternator. If you had a pair shorted then you would be powering up one leg of the windings. This would make noticable heat. If you let the car cool off to stone cold and reconnect the battery lead after a few hours the alternator would at least be a little warm after an hour or so (as long as the battery wasn't dead).