My only BCM code is B0432 which is a rear defroster circuit open code. My control unit for the AC (it's a manual, so 3 ***** and 4 buttons) goes dead from time to time (no lights, no control of the AC, but changing the vent selector causes the defroster door to move up in the dash).

I noticed tonight that while this panel is dead, in my DIC, my instant mpg with the car not running goes 98.6, 98.8, 99, my average mpg is back to zero and my range is "low" with over a 1/4 tank.

The grounds where all good when I replaced the interior 3 weeks ago. Nothing is wet.

Anyone have any ideas where to start? Is it likely the control panel itself?

Bad BCM?

 

I **FINALLY** found the B0432 diagnostic in eSI (I hate the 97 manual with a passion ).

I'm going to try that diagnostic tomorrow and see if it clears everything up, but at this point, I have to believe it is more involved than the redefroster relay being bad.

 

But WAIT! There's more!

I posted a thread a while back about some weird headlight issues (basically, headlights off, they pop up and illuminate, but no dash lights, until you switch the lights on...).

I was just out to pull the car in and I got in the car and got the "wait 10 seconds" message. Waited 10 seconds, started right up like normal. I pulled it in and noticed the AC unit had indicator lights and the instant mpg was back to zero. I flipped the A/C on and messed with the ***** to see if I could make the thing go off again.

The lights came on with the switch off again. Then, the A/C went dead (lights still on lol). The radio lost several hours. I got the lights to go off several times, but *poof* they'd come one again if I did anything. Finally, the lights went off and stayed off, but the A/C never came back.

So I know this has to be a short somewhere in the dash. I've just got no idea what could cause all these symptoms.

Maybe I missed a ground?
Maybe the BCM harness is pooched?
I doubt this is the BCM as I had the lights problem with another BCM as well.

Any idears of what to start looking at?

 

I took apart the driver's side door ground pack again, sanded the contacts and reinstalled. I tried getting the pass side off but with all the stuff in the car, it didn't happen (not feeling super today so I was tired).

Plugged it all back up and the A/C is working mostly. I had one little incident where it turned itself off, but I cleared B0432 (HC) again and after restarting the car a few times it seems to have cleared up -- I just get B0432H now. I can even turn on the rear defroster (but am not really sure if its working -- I didn't want to leave it on for long).

Now, the grounds were not corroded at all (I cleaned them with electronics cleaner 3 weeks ago), but maybe pulling them apart, or sanding them did the trick (it felt tight initially so I think it I had it in there good as well).

The headlights... well, I believe that's a switch issue. If I turn the lights on and then turn the switch all the way to off without pause, the lights pop up. If I roughly hit the turn signal, the lights come on. If I turn the lights on, then stop the switch from rotating right before the off position, they go off and if I hold there a few seconds, they stay off, even when I release the switch and it fully returns to the off position.

Stayed tuned for the next installment of...

ADVENTURES IN THE 98.8th DIMENSION

 

BTW, plan of action is:

See if I can cause a failure by jiggling the DS ground pack
Reinstall the newer PCM and ignition switch (check both the PCM and switch) over the weekend
I may replace the light switch -- it's kinda ratty anyway

 

Ha!

Thanks to this thread: http://forums.corvetteforum.com/c5-t...f-replace.html

I found my headlight problem is common and caused by melted plastic (I think the first mention is on page 2 of that thread). I"m gettin' her fixed (plastic weld is curing as I type).

I also followed Bill Curlee's ignition switch fix thread (http://forums.corvetteforum.com/c5-t...ch-repair.html) while I had everything apart -- my 97 switch was nasty (and I bet that contributed to the modules going out as BC mentioned in his thread), and the 2001 switch needed a spot of love as well.

 

Update: the ignition switch was the problem! No more problems with the a/c panel.