Not sure where to start here but hoping for some direction. My mother in law has a 95 B3000 with a slow electrical drain. I figured I could track it down for her but need some help.

The first problem I found was that it didn't need a key to start it. I was hoping to just replace the cylinder and be done. Maybe the acc circuit was being left on somehow by not turning the ignition off completely.

Second problem is that the dome light does not go off until you start the truck. Once started it seems fine. It turns on and off with the dash dimmer switch. She has just been leaving the bulb out but there is still a drain.

I put in a new cylinder and no changes to the dome light. Starts with a key now but didn't fix the drain yet.

First question is what would be triggering the dome light. I was thinking a door being open but I don't see any switches on the door to trigger anything.

 

Door switch is on the latch for each door, bottom of latch inside, have to pull the door panel to get to it

You have to remove the latch to change it but you can unplug it, that simulates door closed, some try WD40 into the latch, it runs down into the switch and can get it working again

1995 is the first year for the GEM and Battery Saver Relay
GEM, generic electronic module, is the Body computer, it runs the door open dome light, wiper/washer, power windows, power door locks, 4x4
Manual dome light switch is a different power path

The battery saver relay is suppose to "open" after 20-30 minutes of key off, this would turn off any lights that may have been left on.........................
The GEM "opens" it

Best way to find a drain is to hook amp meter up to between disconnected battery cable and its terminal, then pull fuses out one at a time and check if amp draw changed
Pull out fuse #27 in cab fuse box, that simulates Battery saver power being cut

Normal amp draw is .03-.07 amps, this will not run down a good battery for at least a year
If pulling fuse 27 drops amp draw down to that range then the battery saver relay may be stuck closed, unlikely but possible

Otherwise keep pulling fuses

Also a heads up about batteries, they can be self draining, so unhook the battery from vehicle and see if it still drains overnight

A new battery should show 12.8volts
3 year old battery 12.5volts
5/6 year old battery 12.3volts and time for a new battery

12.2volts or lower is a failing battery
But a battery can be self draining even if new, shorted cell inside

 

Thank you. That definitely helped.

I pulled the door panel and the switch was unplugged. Guessing the PO unplugged it since the switch was stuck. I lubed it up and it seems to work fine now.

I'm thinking I still have a key/ignition issue. With the keys in my pocket when I open the driver door the chime starts going. Is that normal for Ford? I thought it would only do that with the keys in the ignition.

The dome light still stays on so I let it sit to see if the GEM would shut it off. After 20 minutes it was still on but I went back after an hour and the light was off. As soon as I opened the door though the light came on and the door chime started beeping.

I haven't started chasing the drain yet.

 

There is a wire in the key switch that detects "key in", thats probably also disconnected or grounded, can't remember which one activates it
You can remove steering wheel covers to have a look

OR..............chime also activates if lights are left on, so main light switch issue, which could also drain power since its hooked directly to battery power

 

Ok, fixed the key in wire. It popped out somehow. Chime is fixed.




Still have the light staying on issue. Going to pull the ignition switch and see if I can move it manually and change anything.

 

I think I have it figured out.

Finally googled the right words and found this.
That fixed the dome light and I don't see any issues it caused.

I'm measuring a .183 draw now so that sounds ok. I'll keep an eye on it for a couple days to verify.

 

Thats too high a draw, should be .03 to .07 after Battery Saver Relay opens, so pull fuse 27 to simulate battery saver relay opening and see what amp draw is then

Good work on the other stuff

 

My #27 says interior lights. After I trick the door sensor into thinking it is closed I get .183 to .187 amps. No change with the fuse in or out.

My #25 says GEM system, instrument cluster. When I pull it I drop to .0045 amps.

 

Yes, 27 is interior lamps

25 is SLEEP power for GEM/timer module so it can detect door open and turn on the lights, so is needed to activate power in fuse 27
25 needs to stay

There are 3 power draws with key off and doors closed and wait for 30min for GEM to go to SLEEP
Radio presets
Computer memory
GEM timer<< also used for keyless entry if so equipped

All 3 should be .07 max amp draw

 

I think I've got it this time. I wasn't waiting for the GEM to go to sleep.

I let it sit for an hour then rechecked. With all fuses in, doors closed, no lights on I'm getting 5.3ma. Sound right?

 

Yes, Good work

But 53ma, thats .05amps

 

I need to burn my shop down so I can't stop being everybody's mechanic. Much more fun working on my toys.

Thanks for the help.

 

+1 on that

I have tightened a fan belt for a friend and then a month later their radio doesn't work and its my fault, lol

"No good deed goes unpunished",it's soooooo true