Automotive Air Conditioning Information Forum

Vehicle: 2005 Acura RL
Problem: Gauge reads 75psi on both high and low side after adding 1 can of R134a
Prior action: Have replaced compressor twice and expansion valve once
* First compressor replacement was because original one was leaking. This was a cheap Chinese compressor.
* Second compressor was after installing first replacement the pressures were equal: same as above. This is an expensive Denso compressor.
* At this point, the only thing I knew to do was to replace the expansion valve. But, even after this, the pressures are the same.[/list]

At a loss for what to do next. Will appreciate any help. Thanks.

It sounds like the AC clutch on the compressor is not engaging. Is the CENTER part of the compressor actually turning, or just the outer rim of the pulley?

I would approach this by first recovering the refrigerant that's in it now, pulling a good vacuum for at least 30 minutes, and weighing-in the factory-specified charge of 19.0 ounces of R134a. Then take LP and HP gauge readings at an engine speed of 1,800 RPM with the A/C system on and report the pressures here. Leak-checking the system at this point is also a good idea since you thought the system was low on refrigerant and you added a can (hopefully without any sealer or enhancers in it). The 75 PSI readings you have now sound to me like static pressures (A/C system and engine off).

If you have only about 12 ounces in it (one can), it is way too low. And as Cusser alluded to, the compressor won't engage.