Need help, no power going to ac compressor (evo 8)
 

Hay guys I was outside this evening trying to recharge my ac system. I would turn the ac on in the car and the compressor would not kick on. To keep a long story short, I ran a jumper wire from the positive terminal to the ac compressor and the compressor came on. I checked the wire that goes to the compressor with my test light while the car was on and got nothing. I checked all the fuses and swapped all the relays.
Does anyone have any idea why the wire that goes to the compressor would not be getting power?

Thanks in advance!!!

too much pressure on the high side or not enough pressure on the low side. Or maybe an issue with the pressure switch itself or associated wiring.

Would either symptom cause no voltage to the wire what so ever?

Yes the ecu won't send a signal if it's not getting a read through the pressure switch

Ok very good.

I'll try to check the pressure on each side.

Thanks!

I just checked the high side and low side and there is no pressure in either side and the wire still will not get power.

Well thats your problem. If you have no pressure your system is empty. You said you just refilled your system right? That's usually only necessary if you have a leak.

Time to break out the tracer dye! :P

Well I tried to refill it and the wire would not get any power going to it.

When I jumped a wire from the positive terminal the clutch kicked on.

Do you have an r134 manifold gauge set? What are your low and high side pressures? You may be overfilled tbh. Either condition will not allow compressor to run . DO NOT force the compressor to run until you know you're not high or low on refrigerant, that's an awesome way to grenade the pump.

If you're 10000% sure you have the correct level of refrigerant then look into replacing the pressure switch. This will require you to recover the existing r410 and recharge.

I dont have a r134 manifold gauge but my buddy is bringing his by tomorrow.
I took off the high and low caps and manual pushed in the release pin and absolutely nothing came out of each side.

Then you have no freon in the system. You will need to pull a vacuum on the system before it gets recharged. When you start filling the system, the compressor should kick on when it gets enough freon. I typically use the little bottles from Autozone to fill systems at home. You just need an adapter so you can hook it up to the gauges your buddy has. Be sure to look at the sticker in the engine compartment to see how much you need to add in oz.

Looks like this.

https://cimg6.ibsrv.net/gimg/www.evo...533e92c0ed.jpg

Ok sounds good, I will try it tomorrow and report back.
Thanks!

make sure you pull a vacuum on the system. air and non condensable gasses are no good for a a/c refrigerant system. also, as said earlier did you check to ensure you dont have a leak somewhere?

Yes I checked for leaks and did not find any...