2003 C5 Battery Drain problem
Thread Starter
8th Gear
Joined: May 2013
Posts: 8
Likes: 1
2003 C5 Battery Drain problem
I have a 2003 C5 convertible, 6 speed, 40,000 mi. Mostly always garage kept and rodent free. My battery went dead, it was 8 years old, I bought a new one. The car deserved it. New one went dead it a couple days. I have been through the complete electrical system and still have 0.469 amp draw with everything off and asleep. I put a blade disconnect of the negative battery post, it allows me to open the blade and run current through my fluke amp meter after I shut the car down and the engine off and let everything go to sleep. After about 5 minutes I check the meter and it shows the 0.469 draw. Pretty consistent in the draw, not erratic. I disconnected all fuses max and small in the BCM and under the hood. I have disconnected the PCM, BCM and Suspension Control Module. I have disconnected everything while observing the amp meter. Never varies, still has draw. Help!!! Any ideas greatly appreciated.
Moderator, Tech Contributor
Joined: Sep 2013
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From: Cape Coral, Florida
I have a 2003 C5 convertible, 6 speed, 40,000 mi. Mostly always garage kept and rodent free. My battery went dead, it was 8 years old, I bought a new one. The car deserved it. New one went dead it a couple days. I have been through the complete electrical system and still have 0.469 amp draw with everything off and asleep. I put a blade disconnect of the negative battery post, it allows me to open the blade and run current through my fluke amp meter after I shut the car down and the engine off and let everything go to sleep. After about 5 minutes I check the meter and it shows the 0.469 draw. Pretty consistent in the draw, not erratic. I disconnected all fuses max and small in the BCM and under the hood. I have disconnected the PCM, BCM and Suspension Control Module. I have disconnected everything while observing the amp meter. Never varies, still has draw. Help!!! Any ideas greatly appreciated.
Try disconnecting the alternator B+ cable...bad diode can cause a parasitic draw !!...OH, and welcome to the Corvette Forum !!..WOW, 8 years old !!...replaced mine today...was almost 6...got the AC Delco Professional...always !!
Last edited by C5 Diag; Jul 29, 2020 at 06:27 PM.
Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 594
From: Prescott, Arizona
You could also try pulling both seat circuit breakers in the passenger side foot well fuse center. Failing seat switches are often the cause of rapid (overnight) battery drain. My car had that problem. As soon as the seat breakers were pulled, I was able to charge the battery and drive the car while I waited for a new seat switch to arrive. Just make sure the driver seat is where you want it before pulling the breakers. Everything works except moving the seats with the breakers pulled.Turned out it was the driver side in my case.
Thread Starter
8th Gear
Joined: May 2013
Posts: 8
Likes: 1
I found the drain from fuse 25 which is the BCM and IPC (instrument panel cluster) supply. I unhooked the BCM completely and still has the .42 amp draw. So I am assuming it is a problem in the IPC. Any ideas on where to go? Thanks.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,497
Likes: 3,999
From: Cape Coral, Florida
About 8 threads below yours another member is having the same issue !!
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Thread Starter
8th Gear
Joined: May 2013
Posts: 8
Likes: 1
2003 C5 Battery Drain problem
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?
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?
Thread Starter
8th Gear
Joined: May 2013
Posts: 8
Likes: 1
Battery Draw Disappeared
Good News - Bad News. I disassembled the complete dash to get to the gauge cluster. The draw disappeared. I drove the car for about 3 weeks without the dash assembled and everything plugged back in. No draw. Assembled the dash back together. No draw. It has been about a month of driving and no problems. I have no idea what could have caused the DIC backlights to be on dimly all the time, but they work great now. Thanks to all who responded. A real head scratcher for me, But I learned a lot about he electrical system for my Vette. Bu the way I spent 21 years as a Field Service Rep troubleshooting Construction Equipment and a Fluke Meter was my best friend. I will keep you posted, I ma sure something will resurface.
Oh one other thing, the oil temperature switch did not work because years ago when the headers were installed they burnt the connector and ruined it. It was not hooked up, but the wiring did not have any
damage or short in it.
Oh one other thing, the oil temperature switch did not work because years ago when the headers were installed they burnt the connector and ruined it. It was not hooked up, but the wiring did not have any
damage or short in it.
Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
DIC buttons backlights always ON
. In addition to that, there's always the feeling that the problem can happen again at any time... 
I was reading this thread with great interest. Something like this happened to my car (DIC buttons backlights always fully ON, not dim, but not extremely evident unless it was dark) and my only way out was to replace the IPC. Please, if you get to the bottom of this let us know your findings
Last edited by GCG; Sep 16, 2020 at 11:57 AM.
Race Director
Joined: Oct 2004
Posts: 12,860
Likes: 4,661
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?
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?
Race Director
Joined: Oct 2004
Posts: 12,860
Likes: 4,661
Glad everything is fine now, but I hate it when things get "fixed" by themselves and the mystery gets perpetuated . In addition to that, there's always the feeling that the problem can happen again at any time...
I was reading this thread with great interest. Something like this happened to my car (DIC buttons backlights always fully ON, not dim, but not extremely evident unless it was dark) and my only way out was to replace the IPC. Please, if you get to the bottom of this let us know your findings
. In addition to that, there's always the feeling that the problem can happen again at any time... I was reading this thread with great interest. Something like this happened to my car (DIC buttons backlights always fully ON, not dim, but not extremely evident unless it was dark) and my only way out was to replace the IPC. Please, if you get to the bottom of this let us know your findings
Last edited by grinder11; Sep 16, 2020 at 02:58 PM. Reason: Spelling