Deepa

I've been having a few issues with my 91 recently. First was an issue with the speedo going blank, sys flashing on the dash, and I ended up replacing the ECM due to code C41/H41 in the CCM.

Even after the replacement, I would get the sys flash at key on at times, but then I would key off/on one or two more times and the car would run without the CEL and not in limp home mode like it would if I just started it when sys was flashing at key on. Other times, I would key on without issues and the car would be fine. The LCD/speedo never went blank on me again.

Fast forward a few weeks with the sys problems, the battery has been dead after charging it the night before. I took the battery to Advance today and it tested out fine. Date of the battery is 6/12.

Today I started working on the draw. It would be an erratic reading such as .25 -.41 ma but then settle down to .12 or so with the doors open. I pulled all of the fuses and started to reinsert them one by one.

These are the fuses/breakers which added draw to the battery...if the fuse/breaker isn't listed, there was no change on the battery draw. These numbers are the amount of draw added to the battery, not my total draw with everything reinstalled.

PWR AC Breaker (4th one down out of 5...hard to read label) - .01 MA
Radio Fuse - .06-.09 but with my ipod adapter turned off it was .02-.04 total draw
Courtesy Fuse - .02 MA
LCD Fuse - .20 - .32 MA draw erratically bouncing between those numbers

With everything connected and the LCD not acting up, total was .05 but when it acted up it was .25-.41 which is way above the .05 which it should be. Other times it would settle at .12 MA and drop to .04 with the LCD fuse them removed.

Has anyone ran into an LCD being a pain in the rear before? Can this be related to my sys flash and CODE H41 in the CCM which means communication lost with the CCM. That code is why I replaced the ECM in the first place. If somehow the LCD is in the path of communication from the CCM to ECM or it gets pinged for a response I hope these problems are related.

Looking for ideas and help with this.

Would a rebuilt cluster fix this? I still need to clean and check the grounds on the engine block and will do that at the next oil change. It also seems like I'll be dropping column and checking the connections at the back of the LCD. If they weren't so expensive, I would be replacing it because my Oil temp gauge is inoperative but the reading is fine on tts datamaster.

Thanks,

Mike

ynot d

When I worked for chevy we were told that the draw should be 30 to 50 ma with interior lights off. If higher you start pulling fuses one at a time until you find the one that drops the reading into the acceptable range. If after pulling a fuse, there is no change replace the fuse and pull the next one. Once you have identified the circuit causing the draw, check the circuit and everything on it for the source of the problem.

Deepa

I tried that procedure first but because the problem is intermittent, it was very hard to see which fuse/circuit was the issue. My other solution was take everything out, then reinstall one at a time. This led me to seeing the LCD circuit is having issues.

My issue lies in the LCD fuse. I am looking for peoples ideas on what is part of that fuse and if the cluster being rebuilt would fix that.

Thanks

Mike

WVZR-1

The LCD fuse I believe powers also the "tone generator". Do you have issues at all with any of the chimes? I think it would be good if you could maybe borrow a cluster before just rebuilding yours in an attempt.

The tone generator I believe I've read that people have repaired/re-soldered the connections on the board. I believe the removal of the dash pad might be the easiest access to replacement.

Are you using the DIC module to check for CCM codes? Scanner?

Deepa

First off, I used the paperclip method.

Now that you mention it...my door chimes are very funky. Sometimes it'll chime once or twice and make me wonder "wtf was that"?

I think you're onto something as the problem is usually when i open the doors after getting out as I normally leave the keys in the ignition but I pull them out slightly.

Hmm this is going to get interesting. I wonder if I could disconnect the dash cluster and then look and see if the irregular/erratic readings are still present after keying on/off a few times while messing with the headlights to make the chime module act up.

Any more ideas? I would like to be certain before I pull the dash pad.

Thanks,
Mike