Air Conditioner only works on defrost?

Thank you for your response. Correction, it is the mode door actuator that I’m replacing. Also, I took apart the mode switch on the dashboard and cleaned the contacts on the inside of the knob.

Normally as long as the fan was on and the A/C button was pushed, the green light would turn on and I could use different modes with the A/C working. Now it just works on defrost.

My main question here is, does the mode door actuator have to be connected in order to turn on the A/C? Right now, that motor is out and will only get A/C when defrost is selected. What I did was move the controls behind the dashboard by hand to make the A/C blow out the dashboard vents until I get the mode actuator installed.

To follow up the mode door actuator was installed and works properly, however, the air conditioning only works when on defrost. Is it possible it’s a mode switch on the dash that’s the problem?

It has manual climate control. I’m almost suspecting it’s the actual A/C button itself. When I pull the relay and use a test light, it’s the same two terminals that stay lit with the button pressed and de-pressed. My thoughts are if the A/C button was doing its job it would make one of the other terminals light up.

Thanks! I will definitely test this! I did swap out the horn relay with the AC clutch relay and it was still doing the same thing.

This is a manual climate control system.

I ordered an A/C button from Walmart for $10.00. I’m going to replace that as well and see if that’s the problem.

One thing I want to mention is when I had the climate control panel out of the dashboard looking at the connections on the switches the 10A magnetic clutch fuse under the hood for the A/C blew out. I replaced it with a 30A fuse. The A/C ran for a little bit then stopped. The 30A fuse was fine when I checked it and the A/C will run fine, but only when in defrost.

Hello,

The issue has been resolved and it was the A/C button.

The two facts that led me to it being the button inside the car were.

The “Clutch Mgmt” relay under the hood was taken out and upon pressing the button to turn on the A/C, the contact that should have made the test light illuminate didn’t light up.

Upon disconnecting the wiring clip with the 5 wires that goes to the back of the A/C button, the blu/red had live power as it should have. However, it was not completing the circuit inside the switch to transfer voltage to the red/blk wire which tells the compressor to turn on when the fan is on. To figure this out I took a paper clip, placed one end on the blu/red contact and the other end on the red/blk contact. Lone behold it turned the compressor on regardless of what mode the fan was on.

Thank you, Joe, for your help in this and hopefully someone with this same issue can efficiently resolve this with knowledge shared here.