Question: 2003 C5 Battery Drain Problem

[Hapyme03]

I have a C5 2003 50th Anniversary Convertible, 6 speed. 40000 miles. Battery went dead (7 years old), I replaced it , new battery went dead after about a couple weeks. Found amp draw on fuse 25 in inside floor fuse holder, it is drawing 0.41 amps when fuse is reinserted in fuse panel. Fuse 25 is for BCM and the Instrument Control Cluster. Disconnected BCM and draw still there. 0.41 draw will stay there no matter what. Any ideas what the draw in the Instrument Control Cluster could be? I am not too keen on taking the dash apart to trace it. Will leave that as my last resort. HELP. Thanks for reading. No related fault codes has come up, but an open to the oil temperature switch came up once. Oil temp gauge is working now, code went away. 0.41 amp draw is hiding.

 

[Hapyme03]

I have a C5 2003 50th Anniversary Convertible, 6 speed. 40000 miles. Battery went dead (7 years old), I replaced it , new battery went dead after about a couple weeks. Found amp draw on fuse 25 in inside floor fuse holder, it is drawing 0.41 amps when fuse is reinserted in fuse panel. Fuse 25 is for BCM and the Instrument Control Cluster. Disconnected BCM and draw still there. 0.41 draw will stay there no matter what. Any ideas what the draw in the Instrument Control Cluster could be? I am not too keen on taking the dash apart to trace it. Will leave that as my last resort. HELP. Thanks for reading. No related fault codes has come up, but an open to the oil temperature switch came up once. Oil temp gauge is working now, code went away. 0.41 amp draw is hiding. I Should have said Instrument Panel Cluster, not instrument Control Cluster (IPC)

 

[gmjunkie]

C5's have a small parasitic drain (.025-.045 Millie Amp) Some will go 6 months without being started,Others only 3-4 weeks depending how equipped. I've found that my 03 will go dead in a couple weeks if my keys are in my desk drawer in my office,(about 10 feet from the car) but if I stick them in my tool box about 60 feet away,It can set there for weeks! If the fob is to close,The car will not go to sleep!

 

[Hapyme03]

I have found out a couple things. Number 1 a code is showing that is an open in the oil temperature sender and the DIC always just shows oil temp low.. I have bought a new sensor, but have not installed it yet. A short in the sensor to cause a drain? I don't know.
Number 2 and I believe the this is the drain. I was very dark the other night, I went out and started the car, shut it off and just sat in the seat, everything timed out and shut off. EXCEPT the backlights on the DIC stayed on very dim. Nothing I tried would turn them off. I am about to take the dash apart and unhook the gauge and cluster and see if he drain stops. I am betting it will. Now should I have the cluster repaired or buy another. The mileage thing always comes up when replacing, but someone posted a thread that showed the location of the mileage chip.
Has anyone ever used Specmo Electronic Repair Service in MI?

 

[grindereleven]

I had my battery go dead overnight a couple times, both times in a very inconvenient situation. Found out the Body Control Module (BCM) was bad. Sure enough, replaced it with one of the last new ones available in 2014 (made a Grand look not so grand!), and problem fixed. Yes, repaired BCMs are much cheaper, but they only have what went wrong repaired. My car is 20 years old, so on the advice of an electronics guru buddy, he said buy a new one. As fussy as these cars are electronically, with everything new, at least you start out with all new conponents. When it does eventually fail, you wont be fixing something with, maybe, 25 year old electronics inside. At this point, repairing one is our only option, unless you're extremely lucky. I've heard the BCM can drain the battery quickly if every component inside doesn't shut down in exactly the proper sequence when you shut off the car. Hope this helps.....