KR81

I'm hoping to try sort out my air con as the next project on my car. 88 Tpi trans am.
It has never worked in the 8 years I've had the car.
I want to learn as much as I can about the system before I take it to an a/c guy or auto electrician so I can tell them about the set up to help save on labor and in case they try to scam me 🤷🏽‍♂️
So it has never worked, doesn't even turn the auxiliary fan on when I put it on an ac setting.
Are there relays/fuses for the ac system?
Can anyone offer reasons why it wouldn't turn on the fan ? I'm of the understanding that even if it has no gas, it should still engage the auxiliary fan when switched on and to an ac setting.
Any help would be appreciated.

KR81

Also the wiring connection for the compressor looks like this, has done since I bought the car, I leave it disconnected now.

OrangeBird

iTrader: (1)

Hi KR81,

First things first, If I'm seeing it right that ugly pasty looking goo in the A/C compressor's clutch connector is an anti corrosion paste that was put on when it was built, so it belongs there. leave it alone and plug the connector back in.

Now, next up is the #1 reason these A/Cs stop working, which is because the refrigerant leaks out. And that's likely what you've got going on there, a leak with the resulting empty system.

As to your aux fan, I looked up the wiring diagram and there are three things connected to the aux fan's relay coil, an "Auxiliary coolant fan switch", a "Fan A/C pressure switch", and the ECM itself, by means of the grey wire connected to terminal "C2 D11" . So, I know the coolant switch will only turn it on when the engine gets too hot and I know the pressure switch will only turn it on when there is A/C activity resulting in refrigerant pressure closing the switch. What I don't know is if the ECM connection will allow the ECM to control the relay, or it that connection is there for merely informing the ECM that the relay has been engaged. If it's able to control the relay then perhaps it could run the fan whenever the A/C is in the on position If the ECM is otherwise informed of the position of the HVAC controls, but if it's simply the ECM monitoring the relay then it will only run under either one of the two switches control.

PS , To test the fan ground the grey wire at whichever switch is easier to get to with the key on and the fan should run.....

KR81

Thanks OrangeBird,
I do know the fan works as they both come on at 220(according tothe guage), I have a switch that turns the second fan on earlier than the stock one, which is 238 I think...

The wire connection is actually melted! Not a paste!