(90 dx hatch d15b2 if it matters) So I replaced the radiator, connected everything, coolant change, bled the air out and everything was good. Fans turn on when temp is reached but won't turn on when the ac is on. Compressor? Or maybe wiring to compressor? Already checked all related fuses. I know the wiring to the fans is good because they are working when temp is reached. So it has to be something with the compressor right? Oh and the fans were turning on for the ac before I replaced the radiator. Now they aren't.

 

I think the fans only run when the compressor is actually running. Have you verified that the compressor is running when you turn the AC on?

 

Yeah that's how I noticed they weren't turning on. Because I turn ac on and they don't kick on and no cold air. It was working fine before I replaced the radiator. Then right after I put everything back together it wasn't working. I'm just wondering if I disconnected any wiring to the compressor while changing the radiator or something like that and if anyone knows what connects to the compressor in regards to the fans, so I can check that out.

 

If you're not getting cold air, my guess is that the compressor is not running. On EFs, the compressor clutch connects to the harness with a simple bullet connection that has a small rubber boot over it. I'm betting you accidentally unplugged this when you replaced the radiator. Look where the hoses go into the top of the compressor and follow the wire that you see there. If it's not connected, plug it back into the car's wiring harness and give it a shot.

 

Thanks for the info, I'll check it out today and see if that was it.

 

Did you jump the low pressure sensor to see if it kicks the compressor/fans on?

 

No because the fans come on when the temp reaches the right temp. So I know the fans are good. It's just the fans don't turn on when I turn the ac on and the ac isn't getting cold. So it's something from the compressor or wiring. Just not sure because it was fine before the radiator replacement and now it's not. All wires are connected to the compressor fine and both fans are plugged back in. There is this piece of wiring that looks like it's not connected completely but I can't tell if it is supposed to be like that. I'll put a picture so every can see what I mean.

This wire connects to the compressor. You can see there is no wire in between. But it looks like it was done like that. The ends of the wires perfectly cut and press in where they are.

 

Could this be it?

 

Yeah that's it. You are missing the rubber boot - likely dry rotted and fell off. You need to put something around it to insulate it. If it grounds out, you will likely blow the fuse. That may be your issue. Insulate it and check the fuse.

 

If the fuse is the culprit, you can ignore my comments. But the switch I mentioned is part of the wiring. The compressor and condenser fan will not engage if there is inadequate pressure, or if the wiring is loose, or if the switch is bad. The main cooling fan is separate from the AC and would not be affected by any of the AC wiring - It should come on when up to temp regardless.

The pressure switch is right around the left side (passenger) of the radiator, on the high pressure line. Maybe you bumped into it when you were replacing the radiator? If the fuse is good I would still suggest jumping it and seeing if the AC engages.