Battery Drain--could be computer?

[lizzardfire]

Re: Battery Drain--could be computer?

Is there any way of determining where this stuck relay is?

[bigbrian442]

Re: Battery Drain--could be computer?

I have to look at what those wires go to in my GM manual when I have time this week end.

[bigbrian442]

Re: Battery Drain--could be computer?

Red .......... Battery positive voltage
Brown .......... accessory positive voltage
Black .......... ground
Orange ........... Battery positive voltage
Blue ........... retained accessory power
Blue/White ........... courtesy lamps feed


Looks like this plug feeds the BCM.

[lizzardfire]

Re: Battery Drain--could be computer?

OK, so you think the problem is inside the BCM then? I have this draw even when that's the only plug that is plugged in... so it seems to me it either must be something inside the BCM or one of the three "non-feed" wired you mentioned--the accessory + voltage, the RAP, or the courtesy lamps feed. I'm not sure how to determine which of these it is without cutting the wires.

[bigbrian442]

Re: Battery Drain--could be computer?

You can "poke" a test light lead in the the insulation on the wire.

[lizzardfire]

Re: Battery Drain--could be computer?

I didn't use a test light because I was afraid there would be the possibility of multiple draws. What I ended up doing was cutting all of the wires except for ground and then reattaching them one at a time. It turns out all of the draw comes from the orange wire, which you have listed as battery positive voltage. If it is indeed directly from the battery, I would imagine that this means that a relay inside the BCM itself is bad.

Bigbrian, is the orange wire connected directly to the battery? Does it sound like the BCM to you?

By the way, you've been an amazing help, thanks again!

[bigbrian442]

Re: Battery Drain--could be computer?

Looks like the orange wire goes to the fuse block, fuse 8, courtesy lamps. Not sure if it feeds that fuse or gets power from that fuse.

[lizzardfire]

Re: Battery Drain--could be computer?

I'm pretty sure that it gets power from the fuse block based on the few wiring diagrams I have in my Haynes manual. As a result, I guess I'm going to go ahead and try to replace the BCM... I'll let you know how it goes.

[lizzardfire]

Re: Battery Drain--could be computer?

OK, I finally got / installed the new BCM and the drain does not change at all. That means it mus not be the BCM. Any other ideas?

[bigbrian442]

Re: Battery Drain--could be computer?

Stock radio or after market?

[Larrymhemenez]

Re: Battery Drain--could be computer?

get a better battery man geez it will help you out alot dotn get a cheap wal mart battery get an good one I leave my car for 2 weeks never started amd i have an alarm and it starts right up

[lizzardfire]

Re: Battery Drain--could be computer?

Aftermarket radio. In fact, I have a massive amount of aftermarket stereo equipment (three amps in addition to the radio). There are two important things to note though: 1, the amps are on a separate power cable that I always have disconnected when I'm testing the draw. 2, disconnecting the radio does not get rid of the draw.

Larry, I just got a brand-new battery (an Optima red-top). I can assure you that the battery is not the problem. The problem is the stock system draw (so Total - Aftermarket Audio Stuff) is around 70-80mA when it should be below 30.

Edit: I changed the first post to this:

I have an 110mA current draw on my battery when everything is off.
30mA of this is for my aftermarket audio amps, which is fine.
The remaining 80mA is far too high for a stock system draw.

Disconnecting the Body Control Module completely takes care of the current drain problem (lowers from 80 to 6mA)
By cutting wires and disconnecting plugs, I figured out that the BCM draws this much current with ONLY two wires hooked up, the red power wire and the black ground wire.
I figured it was thus the BCM, so I replaced the BCM, but that did not change the current draw.

Other stuff: I don't have an alarm

[bigbrian442]

Re: Battery Drain--could be computer?

When you have the wires on the BCM unhooked with the draw, What stops working?

[lizzardfire]

Re: Battery Drain--could be computer?

Well, the wire that causes the draw is the power wire, so disconnecting that makes everything hooked up to the BCM not work. I'm not sure what all that is, but I know for example that the car won't start and that the interior lights don't work, among other things.

[bigbrian442]

Re: Battery Drain--could be computer?

It's kinda weird that the power feed to the BCM has the draw and none of outputs. Makes it very hard to find.