I have a 1999 coupe with dual zone control. This is my 3rd one replaced,
And once again I can not adjust the controls. The numbers are frozen and won't change. I had my corvette guy go thru the whole electrical system, and couldn't find anything wrong. Any thoughts on my problem?

 

Welcome to the forum.

Afraid I can't help. If the control head has been replaced three times, I'm going out on a limb and saying either something else is taking them out or the problem lies elsewhere.

 

Hard to believe no one else hasn't had a problem. This last one didn't even last a year. Can't understand why it won't keep working. I could understand if I hadn't had the electric system check out. They found nothing wrong. Any help would be appreciated.

 

I would recommend that you take your car to an Auto Electric Shop. The ones I have used employed guys who were expert troubleshooters. Local dealerships would send over "problematic" cars that they couldn't figure out.
Run a Google and Bing search for one in your area.

 

How's your positive battery cable?

Mine (even with a new battery) was becoming very corroded very quickly. Finally, after my '08 one day started making weird clicking noises just sitting there, I just replaced the whole positive/negative battery cable assembly.

Well, what a difference THAT made!!

Previously, my AC would intermittently stop coming out of the dash vents. Plus I was seeing a lot of 'Service This' and 'Service That' messages in the Driver Information Center window. After replacing the battery cables - no more issues!! Everything started working normally! No more AC problems, no more messages, no more rough idle, etc...

I'm sure you know how important a solid, clean ground connection is to all the electronics in a 'Vette. It makes sense that the same rule would apply to the positive side as well. I'm pretty sure that with the intermittent positive connection, all the controllers would keep unlearning everything they knew!

 

Welcome to the forum. Thanks for the info although the OP may not see it since thread is four years old. Might help someone searching the forum.