Electrical drain killing battery

[Ristin]

2000 EB Expy 4x4

Battery goes dead after sitting for a couple weeks. I don't see anything obvious all though the hood light might be a suspect. Are there any known electrical drains I should be looking for?
Thanks

 

[stamp11127]

Yes, rear wiper motor, alternator, gem etc

See the following link:
http://www.expeditionforum.com/f16/parasitic-draw-your-battery-keeps-going-dead-24600/

 

[Ristin]

Thanks.
I was hoping I wouldn't have to resort to pulling fuses. That's a lot of uncomfortable work for a fat guy.

 

[stamp11127]

I hear you, I used to get wedged under the schoolbus fuel tanks when I was working on them. Had a choice to make, keep eating and change fields or diet. Sure going to miss driving those beasts....

 

[docraymund]

No way out, you're gonna have to pull the fuses one by one. Start with the one on the driver's side then go on to the one in the engine compartment. You should be able to find the problem just do it one by one. Mine was the fuse for the rear towing lights. Pulled it out since I don't tow anything and bought a new battery. Ever since, no more battery drain even if I don't start it for a month.

 

[Ristin]

Today's project is brakes all way round and passenger side axle half shaft.

Has to be a fairly low amp drain as the Expy can sit for a few days and start OK.
Had a similar problem with my Civic. I was replacing the gas/truck release cable and left the truck open for a few days. I didn't know the Civic had a trunk light.

My under hood light was hanging by the wire so I'm wondering if it was staying on. I fixed it yesterday. I'll still get out the amp meter and see whats going on.

When I got the truck, several lights like the running board lights were disconnected so I wonder if the previous owner had issues.

 

[Ristin]

Hooked up the amp meter and I have a 300ma draw. Eric the car guy indicates it should be 50ma or less. Didn't have time to pull fuses as we were gone most of the day.

Bad day for batteries at my house. Went to start my dually and both batteries were dead. Something has failed and the interior lights in the doors are staying on. Temporary fix was removing the fuse.

Hooked the Expy to the travel trailer for the first time and discovered A. The tow battery charge circuit was inop and B. the trailer battery was dead. Found the charge circuit relay was missing. Actually had a relay in my spare parts box so I was able to accomplish something.

 

[Ristin]

Pulled fuses today. Fuse 15 stopped the drain. The book says that fuse is:
Stop light Switch (Speed control, Brake Shift Interlock, ABS, PCM Module Inputs, Air Suspension Module, Auto lock) GEM Module.
I don't have air suspension so I can rule that out. Don't know where to go from here.

 

[Bedrck47]

Having factory wiring diagrams would come in handy about now

 

[Ristin]

Yes it would and according to USPS tracking, they will arrive between April 17th and April 21.

 

[Ristin]

OUCH! New GEM in $457. Guess I'll be pulling the fuse when I leave the Expy sitting for more than a few days.

 

[stamp11127]

The GEM hasn't been proven faulty. When you get the factory diagrams look at 90-4 for additional circuits that get power when the brake switch is closed. Bedrck brought that up in discussions we have had concerning this problem. You need to prove or disprove those circuits are energized without the brake pedal applied. If they are not then something has the gem drawing more power than it should. At that point it would be isolating which circuit is causing it or is it an internal problem to the gem. This is where the fun begins...

 

[Ristin]

The voice of reason speaks.

You are right of course and I am not looking forward to tracing this down. Fortunately it only causes an issue when I let the truck sit for 2 weeks. When I'm home from work and drive it every few days the battery can cope. For now I'll pull the fuse when I leave for work.
I have more pressing issues to repair so this is back burnered until I get the wiring diagrams and more patience.
I was thinking GEM because I'm a pessimist and always think worst case scenario.