Electrical Gremlins or coincedence?
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Hey - I said it was over my head! No insults intended - I do know that I haven't been to a dealership in the last 20 years that didn't have the battery charger with jump starter sitting out. In fact, when I bought my '97 S10, they had to jump it and when I got it home, I had to leave it on the charger overnight - it was that dead (but I got a good deal and if I didn't make it home I had my Auto Club card!). As to this a/c thing, I don't believe the CCM has anything to do with it. The Processor is the Programmer. As far as I know, the CCM is merely a diagnostic link - it isn't the signal for anything and the Programmer calculates Temp door position and blower speed based on inputs from the Temp thermistors and desired temp signal from the Controls. Programmer also sends the a/c request to the ECM and that circuit is bridged by the Low Pressure Switch. ECM monitors Pressure Sensor for overall condition and high pressure; on/offs (Low Pressure Switch) for low charge. Foul ups (trouble codes) should be available through the Panel or Speedo and you can emulate the Controls with a bi-directional scanner through the CCM link. Hopefully code(s) will be retrieved soon so that we can help fix the problem.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Originally Posted by KEN W ANDERSON
I stand behind what I said, as we repair Corvette clusters, radios and CCM's for a living. There's more misinformation on the web about these parts than accurate info. GM built no protectection in these circuits from erant sparks for a reason. An 89 cluster has no relationship to an 84, 85 , 86, 87, or 88 cluster except the lower display boards are the same. You guys are guilty of reading some old info on the web and assuming it's gospel because it's there. And then, because I'm new to your forum some moron says I have no manners for printing the truth. Well, I think I've been pretty straightforward about it because I was trying to help the original poster avoid more problems by jump starting his car. You only do that as a last resort if you are stranded a long way from nowhere, but it's his car and he can do whatever he wishes.
I don't understand how you can recommend charging your disconnected battery up and then reconnecting it but insist that jumping a battery is dangerous. The same voltage transient occurs when you do either. If jumping car batteries really can cause damage, then why don't car companies inform owners not to do so? Not one car manufacturer says to not jump a battery.
Former Vendor
Joined: May 2006
Posts: 127
Likes: 0
This is GM's advice for jump starting a C-4:
" If for some reason you have a low or dead battery be cautious when jump starting. When you attach the jumper cables to your battery and ground, wait about two minutes before trying to start the car. This allows voltage to power up the seven microprocessor's circuit boards. This helps prevent voltage spikes into the components."
About 10% of the clusters we repair have a defective IC caused by a voltage spike and we won't even get into the damage done to an alternator trying to charge a dead battery. Jump boxes should be banned at dealerships, but if they weren't I guess we would lose business. There is no built in protection!
" If for some reason you have a low or dead battery be cautious when jump starting. When you attach the jumper cables to your battery and ground, wait about two minutes before trying to start the car. This allows voltage to power up the seven microprocessor's circuit boards. This helps prevent voltage spikes into the components."
About 10% of the clusters we repair have a defective IC caused by a voltage spike and we won't even get into the damage done to an alternator trying to charge a dead battery. Jump boxes should be banned at dealerships, but if they weren't I guess we would lose business. There is no built in protection!
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Just for the record: I have jumpstarted my 86 more times than I care to admit and no harm has come from it.....that is obvious to me. Matter of fact never had a problem after jumpstarting any car.
Sorry shakedown067, this was of no help to you.
Sorry shakedown067, this was of no help to you.
Thread Starter
Le Mans Master
Joined: Dec 2003
Posts: 5,768
Likes: 33
From: Van Steel Corvettes
St. Jude Donor '12-'13
Ok, so I finally get the blinking light again on the A/C. I push the fan buttons and it just comes up with 00. I'll just have to take it to my Vette guy and hope he finds it quick. Thanks for the help.
Cruising
Joined: Sep 2006
Posts: 14
Likes: 0
From: Clovis, California
Did you ever get this problem solved ???
I have a 1990 six speed and have a similar problem (I pulled a CCM code 41 / loss of communications with ECM) ... one of the statements in the factory manual says that "if this fault is present, the C68 Electronic HVAC control head "OFF" LED will flash" ... don't know if the setup is the same on your year or not.
Just was curious to see if the dealership was able to get this fixed ... or not.
I have a 1990 six speed and have a similar problem (I pulled a CCM code 41 / loss of communications with ECM) ... one of the statements in the factory manual says that "if this fault is present, the C68 Electronic HVAC control head "OFF" LED will flash" ... don't know if the setup is the same on your year or not.
Just was curious to see if the dealership was able to get this fixed ... or not.
