A/C Clutch

How can I tell if the ac clutch is engaging? I checked the fuse and relay in the box under the hood. Good. I have a buick century 2005. I also checked the pressure at the low pressure valve when the unit is on and it shows 35 psi which the gauge says is fine.

If you can see the compressor then watch the front of it while someone turns the AC on and off. You should see and hear it engage. It will move slightly and then turn with the belt otherwise it should remain stationary.

Any suggestions what else I should check. I checked the fuse and relay in the box next to the battery. The refrigerant pressure is ~35psi which should be sufficient.

Any suggestions what else I should check. I checked the fuse and relay in the box next to the battery. The refrigerant pressure is ~35psi which should be sufficient.

35 psi is great if compressor is running-- it is rotten if compressor is not runnning- means you've lost 95% of your refrigerant.

Compressor won't come on until static pressure is 47 +psi...

it is 35psi with car and ac turned on. with car off i get over 50 psi. I guess that means that my ac clutch is engaging. But the air coming into the car is warm. not getting cold at all. any suggestions. are there other things to check?

You are low on refrigerant and need to add about 2 cans--- after you find and fix the leak....

thanks for the quick response. Is 35psi good or no good. If the pressures are different with car on 35 and with off over 50 am I correct that the compressor clutch is engaging? anyways do you recommend using the dye to find the leak ? should i use the seal leak stuff. (used it once on an acura and it it still going strong after 4 years)

Most likely a compressor shaft seal leaker...

If you use leak sealer- don't ever bring it to me-- that stuff will ruin a recovery machine!

Dye is already in your system- Dye was introduced in GM vehicle OEM in 2002 model year. Get out your blacklight and UV glasses (sold at Autozone $12) and leak for leak evidence- it will glow bright fluorescent green.