I have a 2001 c5 with 81000 miles on it in good condition. I recently developed a problem with a high current draw,(7 to 8 amps) with everything off and the car parked for the night. Will actually draw the battery, (new Optima) down enough not start in about 5 hours. I disconnected the battery and measured the amperage with an ammeter. If I disconnect the input power leads going into the under-the -hood fuse box, all but about 2 amps goes away. I know this is still too much but I want to find the big draw first. I've pulled all the fuses in both boxes to no change. If I hook up the lead to the fuse box under the pass floor board, it comes back. A couple of threads have been about high draws in the instrument package. Also threads about falling HUD's. Mine dropped out of sight just about the same time this problem happened. Has anybody had this happen to them or does anybody think this is possible?

 

Just for grins, unplug the connector at the alternator and see if the draw changes.

 

I'll bet it's a bad alternator...that's a really healthy current draw...Otherwise start pulling fuses until you find the circuit...

 

got to be the alternator if you pulled all the fuses

 

we had one at work doing the same thing.. make sure its in the "Sleep Mode" before testing. remove all fuses/relays one at a time measuring the draw. if everything is out of the Fuse panel try disconnecting the fuse panel... might be a internal short in the fuse box... if it drop at that point, then replace the panel.

S

 

Okay, I wasn't aware of the sleep mode and kept turning little things off and on. Started fresh this am. With hood light out, both doors closed, key off, it starts off at 6 amps, after 15 min drops to 4.5 amps. Disconnected both connecters from alt, pulled all fuses from under hood fuse box, disconnected Headlights and headlight actuator, and no change. Disconnected both power wires going to under hood fuse box and went to zero amps. Hooked just the wire to the I/P fuse box and it went back to 4.5 amps, after 10 minutes 3.5 amps. Opened pass door to get to fuse box, went back to 6 amps (lights, Etc). Pulled fuses one by one and got following:
Pulled fuse 5 RPO/CD dropped 1 amp
Pulled fuse 23 BCM 2 dropped .5 amp
Pulled fuse 25 BCM & IPC dropped 3 amps
Pulled fuse 29 C/LALDL dropped 1 amp
With these 4 fuses pulled, I'm getting 200 to 300 ma
Other factors. Optima battery was 5yrs and 9 months old, but gave no problem until this happened 2 weeks ago. Fairly good shop in town had it for a week, gave up. Put new Optima I am going to leave everything hooked up tonight and see what happens. All the readings were with an analog meter. I just remembered I had a good digital in the motorhome and right now it reads .21ma with the respective fuses pulled.
I also wonder if the high draw on the I/P fuse could be caused by my HUD completely falling down out of sight?
Any help/ideas would be appreciated.

 

Yes, the dimmer switch is all the way ccw. And this thing has got me frustrated, so the analog meter is reading around 50ma and the digital is reading 20 to 22 ma. I charged the battery up and have it hooked up again with the 4 fuses out to see what happens over night. Let you know tomorrow!

 

Okay, I'm a dummie! 30 years of avionics experience and I took someone's word for where a switch was positioned. The dimmer switch WAS clicked on. I just went and checked it. I've known my mechanic for a few years and he told me he checked it. Teach me to get lazy and take to someone else. I'll see what happens tomorrow.

 

Thanks for info. Where is that dimmer switch located? Is that for the HUD or is there another dimmer switch? Thanks.

 

Thanks for info.

 

Don't let me say,, I TOLD YOU SO,,,, but that another reason to
READ THE OWNERS MANUAL!