Air conditioning Problem
Thread Starter
Melting Slicks
Joined: Sep 2001
Posts: 3,494
Likes: 36
From: Livermore Ca
St. Jude Donor '05-'06
Air conditioning Problem
I’m having problems with my air conditioning. In a 89 Coupe.
I have on of those electronic control systems.
When I set it to 65 degrees warm air comes out of vents.
I have noticed that the condenser and clutch are working.
The dryer and pipes are cold.
How can I troubleshoot this problem to see if it a door, relay and/or control system problem.
I have noticed that the repair books don’t talk about troubleshooting the system.
Thanks,
Todd
I have on of those electronic control systems.
When I set it to 65 degrees warm air comes out of vents.
I have noticed that the condenser and clutch are working.
The dryer and pipes are cold.
How can I troubleshoot this problem to see if it a door, relay and/or control system problem.
I have noticed that the repair books don’t talk about troubleshooting the system.
Thanks,
Todd
Burning Brakes
Joined: Dec 2000
Posts: 1,161
Likes: 0
From: Orangeburg, NY
Re: Air conditioning Problem (Coupe89)
You can check several things; First check the vacum line near your distributor. There should be a t-fitting which does crack or break. Make sure there is vacum in that line.
Check the control mixture door in the heating/ a/c assembly. It is located in the engine compartment on the passenger side. Remove the electric connection and remove the electric module. you can now see inside the unit. There is a mixture door. With a screwdriver (very carefully and with little pressure) try to move the door. If it moves then the clip is broken on the rod connected to the electric door relay (common on 88 and 89's). If it does not move then chances are your control unit is in need of repair. It is located under the driver's dash near the brake pedal. It is black and approx 2"x6". It is held on by one bolt. Remove the bolt and the vacum harness (there is a small bolt in the middle of the vacum lines). Remove the electric harness. Open the unit and remove the transistor board. In the upper right corner are two resistors. See if the board around the resistors is burnt or brown in color. Turn the board over and check the resistor connections. They should be shiny silver. If they are a dull gray or the soldier is broke, that is your problem. Take the unit to a TV repair shop and ask them to either replace or resoldier the resistors (I believe they are 140 ohm). Reinstall the unit. The unit costs approximately $3-400.00 new and replacing the resistors cost .49 for two at radio shack. If you need any further information, e-mail me.
Check the control mixture door in the heating/ a/c assembly. It is located in the engine compartment on the passenger side. Remove the electric connection and remove the electric module. you can now see inside the unit. There is a mixture door. With a screwdriver (very carefully and with little pressure) try to move the door. If it moves then the clip is broken on the rod connected to the electric door relay (common on 88 and 89's). If it does not move then chances are your control unit is in need of repair. It is located under the driver's dash near the brake pedal. It is black and approx 2"x6". It is held on by one bolt. Remove the bolt and the vacum harness (there is a small bolt in the middle of the vacum lines). Remove the electric harness. Open the unit and remove the transistor board. In the upper right corner are two resistors. See if the board around the resistors is burnt or brown in color. Turn the board over and check the resistor connections. They should be shiny silver. If they are a dull gray or the soldier is broke, that is your problem. Take the unit to a TV repair shop and ask them to either replace or resoldier the resistors (I believe they are 140 ohm). Reinstall the unit. The unit costs approximately $3-400.00 new and replacing the resistors cost .49 for two at radio shack. If you need any further information, e-mail me.
