Power Drain
Thread Starter
1st Gear
Joined: Sep 2012
Posts: 1
Likes: 0
Power Drain
I have a 2000 C5 that has something draining the power/battery when parked and off. I've had the battery changed, checked, alternators checked, alarm checked. The last corvette dealer stated it was a wire buried in the dash which took 3 weeks to fix and $$$$'s later. The problem still persists.
I've had 3 Corvette mechanics look at it, and no one can seem to find the problem. Can anyone recommend a reliable/affordable mechanic in California, specifically northern CA.
I've had 3 Corvette mechanics look at it, and no one can seem to find the problem. Can anyone recommend a reliable/affordable mechanic in California, specifically northern CA.
Melting Slicks
Joined: May 2008
Posts: 2,606
Likes: 355
From: Rochester New York
Finding battery draws on C5s and C6s can be difficult because normal battery draw finding techniques can't be used due to retained power from accessories and what not. For example a draw used to be found by removing battery power cable and connecting a test lamp between. When there is a draw the test lamp will illuminate. You can then remove fuses or components to find the draw. The draw is found when the light goes out.
The problem with a C5 is, once you disconnect the battery power, there are a few components that will use battery power momentarily when ever the battery is reconnected. When you connect the test light between the battery positive cable it will illuminate and stay illuminated whether you have a draw or not.
A good way to find a draw in a C5 and C6 is with the use of a fuse buddy: http://www.autozone.com/autozone/acc...er=374613_0_0_
What you will do is leave the battery connected, and make sure all doors, lights and accessories are turned off. You will then remove one fuse and place the fuse buddy in its place. The fuse buddy will tell you the Amperage draw for that circuit. If there is no draw, then you replace the fuse and try the next one. You will do this for every fuse in the panel. Make a note of which fuses have a current draw and the amount of Amps.
It takes time and can drive you crazy. In one case, on a C6 I found the radio circuit to be causing a draw. Once I removed the fuse buddy, the radio must have reset and the draw went away.
On C5s I have seen the drivers seat module causing a draw. Change in a cigar lighter can cause a draw. The BCM can cause a draw. Check and clean all the main grounds.
Good luck
The problem with a C5 is, once you disconnect the battery power, there are a few components that will use battery power momentarily when ever the battery is reconnected. When you connect the test light between the battery positive cable it will illuminate and stay illuminated whether you have a draw or not.
A good way to find a draw in a C5 and C6 is with the use of a fuse buddy: http://www.autozone.com/autozone/acc...er=374613_0_0_
What you will do is leave the battery connected, and make sure all doors, lights and accessories are turned off. You will then remove one fuse and place the fuse buddy in its place. The fuse buddy will tell you the Amperage draw for that circuit. If there is no draw, then you replace the fuse and try the next one. You will do this for every fuse in the panel. Make a note of which fuses have a current draw and the amount of Amps.
It takes time and can drive you crazy. In one case, on a C6 I found the radio circuit to be causing a draw. Once I removed the fuse buddy, the radio must have reset and the draw went away.
On C5s I have seen the drivers seat module causing a draw. Change in a cigar lighter can cause a draw. The BCM can cause a draw. Check and clean all the main grounds.
Good luck
Instructor
Joined: Apr 2009
Posts: 109
Likes: 5
From: Renton WA
Love This Forum!
If you can't do some of the diagnostic work yourself, electrical problems can be VERY expensive to isolate based primarily on the detective time needed to isolate the problem.
Here are a couple of links from the Forum's resident wizard of electrical Mr Bill Curlee. Read through them and there are a few things that you can check yourself:
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.
There are several COMMON things that cause excessive current draw
-Seat multifunction switch & Lumbar Switch
- Bose Amp relay stuck on
- Alternator didoes bad and drawing current
- Headlight control module bad
- Interior light on (check in the dark)
- Added aftermarket accessory not shutting off
Here is the setup to measure the current drain:
http://forums.corvetteforum.com/1567522286-post590.html
Here are a couple of links from the Forum's resident wizard of electrical Mr Bill Curlee. Read through them and there are a few things that you can check yourself:
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.
There are several COMMON things that cause excessive current draw
-Seat multifunction switch & Lumbar Switch
- Bose Amp relay stuck on
- Alternator didoes bad and drawing current
- Headlight control module bad
- Interior light on (check in the dark)
- Added aftermarket accessory not shutting off
Here is the setup to measure the current drain:
http://forums.corvetteforum.com/1567522286-post590.html
