I have an 2001 that has a large battery drain, it will drain a battery in a day if not driven. After running a current drain check, about .75 amps via amp meter. What is normal resting amp draw?

 

Can someone help with this before it hits the Dealership?

 

Couple of suggestions

Do you hear anything running, clicking etc?

With your ampmeter hooked up, try pulling fuses one at a time, you may have something stuck on or you may have a ground. If you get lucky the amp meter will drop noticiably on the guilty circuit. I had a similar problem in a Firebird, ended up beign a chaffed wire that was rubbing slightly and going to ground, took a couple of weeks to find the culprit.


Good luck

 

Start unplugging fuses and watch the amperage.

The current drain when sitting should be in the 10's of milliamps, if that.

Do you have any audio additions or cell phone crap?

 

Do you have a remote CD changer? Some brands cause a drain when the sliding door is left in open position.

 

The correct BCM current draw should be 20 Milliamps or less. Most C5 run around 25ma but I have see some as low as 15 ma.

Leave the engine compartment fuse box for last and start with the passengers compartment box first. Pull the power seat breakers FIRST! The power seats have a tendancy stay on and cause this issue.

Also pull the fuses for the Bose system amp.

Examine the car in the dark for lights staying ON.

Once you prove the interior circuits good,,, check the headlight circuits, and then test the current draw of the alternator.

Look at my electrical stickey. I think I cover this in detail in that post.

BC

BC

 

What fuse do I need to pull, to be able to check the fuses with the door open. Do I need to disable the BCM fuses? My amp draw is high when the door is open, even when I pull the courtesy lamp relay.

 

That is the one I removed, it kills the light , but with the door open there must be some other circuitry that is still energized. Thanks though.

 

i suggest you wait the 15 - 20 min for the system to go to sleep before you check things out if you are not already doing so. this will also turn out the door light so leave the door open and wait. you also need to have your ammeter connected at the beginning because if you hook it up while the system is at rest it will come alive again. what is your draw at rest? or is the .75 at rest? i think the voltage drops at least once before the sleep mode as well. hope i am not telling you stuff you already know. if so, i apologize in advance.

 

You may not be doing the current draw test correctly. The BCM is the key to this test. It CAN NOT be disabled because it controls ALL the body functions which includes the SECURITY SYSTEM which is monitoring your open doors. With the doors, hood or trunk open, the BCM will start a timer and in approx 12-15 minutes, will turn the interior lights OFF and go into sleep mode and monitor the security system and RFA module.

The BCM in sleep mode/ security mode is what the 20 ma current draw is based on. Any time you bring the BCM out of sleep mode, you will need to wait for the BCM to time out and go back into sleep / security monitor mode.

If you hook the amp meter up in series, watch the readings as soon as you connect it. You will see approx 7-8 amps, then 1-2 amps, then it will/should stablize around 20 ma. If it doesnt drop down below .75 amps with in 20 mins,,,something is NOT turning off when it should. If you disturb that connection, start the test over again.

IF,,,,,,you had a service manual, you could fins ALL the fuses that are ON when the key is in the ON/RUN position. Then you could use a volt meter and read the voltage /lack of voltage on those fuses to insure that they are powering OFF when there suppose to.

Like I stated previously, there are COMMON things that cause this issue.

Unplug the drivers and then the passengers seat and see if that eliminates the issue.

Pull the BOSE power fuse.

Pull the fat red wire off the back of the alternator

Pull the head light control module fuses.

Thats the MOST common excess current draw issues.

BC

 

First of all thanks for all you help. After quite a bit of searching we found that it was the drivers seat. We pulled and replaced all the fuses and could not find the culprit. Then we pulled the fuse block, located in the foot well, and discovered that when we removed the middle block of wires the voltage would drop. Then we pulled all the fuses associated with that bundle and slowly replaced them until we found the guilty party. I don't know why the amperage would not drop when we removed the fuses one by one. The fuse was listed as SCM-L.

For future reference. You can trick the car into thinking that the doors are shut, thus eliminating the 15-20 min wait for the system to go to sleep, by closing the latching mechanism in the doors.

 

you still need 15-20 min for the system to go to sleep but you wont have the big draw of the door light. glad you got it isolated