DrTrenga

Hi All,
I have a 1989 C-4 with an A/C - Heater problem.
I think it needs a new head control unit, please let me know if I'm on the right track.
It will not change from heat to cool, the previous owner has put a manual shut off in the heater line, if shut off the A/C blows nice and cold, if not it's always hot. Also it will not change from vent to floor / defrost, ETC.
Has anyone else run across this problem? And if so was the control unit the fix.
Thank you

Mike

AirForceOne!

Found this post, might help a little?

http://forums.corvetteforum.com/c4-t...e-the-car.html

DrTrenga

Thanks AF1 - my brake booster does feel a bit hard, which would explain a vacuum leak, I never thought to chase that - I certainly will now.
Thanks again

theadmiral94

Often the 'head control unit' (presuming the electronic version), just needs to be cleaned.

there is a rubber membrane behind the buttons, which have carbon buttons behind the membrane which when pushed, contact the circuit board behind.

Careful Disasembly of the console and trim ring and then the control head, and then careful disasembly of the control head and gentle cleaning of the carbon buttons with cotton swab with isopropyl alcohol and a gentle cleaning of the circuit board contacts with a pencil eraser will likley restore it to full working order.

Consider doing radio at same time as it often suffers from the same problem.