heater/ac control unit
Thread Starter
Heel & Toe
Joined: Jun 2005
Posts: 19
Likes: 0
heater/ac control unit
in my 89 my ac/heater control unit is electric and sometimes it goes haywire and the lights blink off and on and the numbers change and it cuts off and on by itself.is the unit going bad or is this normal.
Race Director
Joined: Feb 2003
Posts: 16,475
Likes: 270
From: Kingman AZ
Cruise-In VII Veteran
Cruise-In VIII
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16
I took mine out. You have to remove the center trim, then there are 4 - 7mm bolts that come out. It just unplugs. Use a clean pencil eraser to burnish the contacts or spray contact cleaner. It did not help mine. (an 87). The AC/heater functions OK I just would like to have the correct display. You can get a used one from www.vette2vette.com or www.contemporarycorvettes.com
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
DO NOT take an eraser to the gold plated pads on the circuit board!!! You will have connection problems forever, guaranteed. Use either electrical contact cleaner spray or a cloth and alcohol.
If cleaning the connectors doesn't help, then you will have to remove the control head and take it apart to where you can see the circuit boards. Using magnification, examine each solder joint and reflow those that look defective. Also, there is a row of about 1/4" diameter eyelets with a miniscus of solder across each one and these solder webs crack causing the problems you experience. Reflow these if you see poor solder joints on these large eyelets.
If cleaning the connectors doesn't help, then you will have to remove the control head and take it apart to where you can see the circuit boards. Using magnification, examine each solder joint and reflow those that look defective. Also, there is a row of about 1/4" diameter eyelets with a miniscus of solder across each one and these solder webs crack causing the problems you experience. Reflow these if you see poor solder joints on these large eyelets.
