I have a drain on my battery and I'm trying to figure it out. Whatever it is it causes the battery to be dead enough that the vehicle won't start after only a few days, a week max. I got a new battery since the other once had been jumped a few times, so I know it's good. It'll be dead in a week though if I leave the terminals installed.

I got a cheap multimeter and did the whole drain test thing per the YouTube video, granted I don't know a lot about troubleshooting this sort of thing. Here's what I've got with the doors shut, key out and everything just as it sits when parked.



It's initially higher but levels off after about 10 seconds, don't know if that means anything.

I started pulling fuses and the only fuse that got a reaction was fuse #12 in the fuse box under the steering column. With that removed the reading dropped to 0.80, no other fuse had any effect.

So am I going in the right direction or is there something else I should be looking at? From what I can gather that fuse goes to the "multi function unit" which is a mystery to me. Could that be the cause of the drain or is 0.80 still too much and a problem lies elsewhere?

 

Good luck.
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If it's for the sunroof ecu can I just unplug it since I don't use them anyway?

 

Yeah, should be able to remove with no other issues. That fuse info came from the Electrical Library in the Rave download. At least >1/2 of your drain will be gone. I don't recall what "normal" power off drain should be.
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F12 10A in the interior fuse box is the MFU. It also protects the trans range selector switch, CD changer, and service reminder. Do you have the stock radio and CD changer still? The MFU is your interior lights like when you shut the door the lights stay on and then dim and shut off, it also controls the central door locking and radio for the fob. Usually it's a door switch that's bunged, it will keep the lights on or the drivers side door key switch. Range selector would be the solenoid to allow you to move the selector out of park when the brakes are applied. Fun, fun, fun. The meter should show draw in milliamps, not a whole amp or more. Service reminder is the red cube that pops the Service light on your dash.

 

Stock radio, cd changer and amp are all gone. Central locking and key fob function did go nuts semi recently to the point where I had to disable it so I wouldn't get locked out. The fob worked all the time, then sometimes, then not at all. The locks however would randomly engage, usually when opening the rear door which is odd. Should I snag a MFU from the junkyard and start there?

 

If you can snag the MFU real cheap sure but I don't honestly think it's that all in itself. I'd snag it just to have a spare and might help troubleshoot your drain. Something electrical in the lock solenoids sounds like the issue like the cargo door's wiring loom at the crease (exits door, enters body), wonder if you have an exposed wire somewhere in it.

 

Thanks for the correction. Replied thinking this was a D2.

You're definitely the D1 man to help.
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I'll start looking for bad wires back there, it's certainly possible considering the hinges were broken when I got it.

 

I just know the vehicle and where to find the information in the Rave. I also could be the DII man because of how many I've fixed which is the reason I don't own one......

It's a long process sometimes but eventually you find the problem. It's almost never what's suggested but if I can get you looking in the right areas it should pop out at you. A battery disconnect switch isn't a bad idea if you're not using the truck often.