Electrical Issues: LCD Screen and HVAC
Thread Starter
1st Gear
Joined: Apr 2025
Posts: 1
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From: Bellefontaine, Ohio
Electrical Issues: LCD Screen and HVAC
Hello!
I've had my 1990 Corvette for about 7 months, and last Saturday night, two issues started to happen almost simultaneously: The LCD screen that displays the speed, OD, fuel, etc. started malfunctioning and would randomly display gibberish. The HVAC also started acting up and would randomly engage different modes. I found out when I got home that the RPM needle also fluctuates at idle but the engine sounds fine to me.
Since then, the car has done this just about every time I've started it. It will almost always have the LCD issue, and the HVAC is slightly more intermittent, and the tach needle will basically only fluctuate when the LCD is acting up. I thought it might be a grounding problem as these all share G201, but I looked at it and it seemed fine to me. Should I remove it and reattach?
The issues only occur when the Corvette is actually on and running. Could it maybe be an alternator issue?
I drove it for a while that day, and it only started acting up on the way back. Normally, I'd just replace the two parts, but it seems like they may share a common cause.
If anyone has any help, questions, or suggestions, that would be greatly appreciated!
I've had my 1990 Corvette for about 7 months, and last Saturday night, two issues started to happen almost simultaneously: The LCD screen that displays the speed, OD, fuel, etc. started malfunctioning and would randomly display gibberish. The HVAC also started acting up and would randomly engage different modes. I found out when I got home that the RPM needle also fluctuates at idle but the engine sounds fine to me.
Since then, the car has done this just about every time I've started it. It will almost always have the LCD issue, and the HVAC is slightly more intermittent, and the tach needle will basically only fluctuate when the LCD is acting up. I thought it might be a grounding problem as these all share G201, but I looked at it and it seemed fine to me. Should I remove it and reattach?
The issues only occur when the Corvette is actually on and running. Could it maybe be an alternator issue?
I drove it for a while that day, and it only started acting up on the way back. Normally, I'd just replace the two parts, but it seems like they may share a common cause.
If anyone has any help, questions, or suggestions, that would be greatly appreciated!
