828790vetteman

I have recently converted both my '87 and '90 A/C systems to R134A. So far the cooling has been fantastic in the '90, the vent temperatures are around 45 degrees. In the '87 the vent temperatures are at around 55 degrees. What could be the cause for such a difference in vent temperatures between these two systems? With the '90 should the fan come on when the A/C is turned on?

Thanks for any advice!

SunCr if you don't mind giving your opinion, it would be greatly appreciated.

SunCr

Check operating pressures - that's the best indicator of vent temps. Another test would be to run cool water over the condensor. If the vent temp drops, pressure is too high or there may be a cooling fan problem.

'90's fan set up should come on (both actually), a/c on with the 2nd fan spooling up a notch once a certain pressure threshold is reached. '87 fan doesn't come on until 230 psi and will shut off at 170 psi. Check to make sure it's within this range on your manifold gage set.

SunCr

Elkabong: Pressure cycling switch in the diagram is the low pressure switch.

elkabong

Suncr - Thanks. Now I am dangerous......

828790vetteman

SunCr you mentioned that it was possible that my operating pressures might be too high. So in order to correct this I need to release a little refrigerant. If I do this, I am worried about the oil that will be expelled with the refrigerant. I do not want my compressor running on an inadequate amount of oil. How should I go about removing excess refrigerant and making sure that I have enough oil in the system to function properly?

Thanks Ryan

828790vetteman

SunCr, I checked both of my systems last night and they seem to be slightly overcharged. If you don't mind giving me some help on the correct way to remove the excess refrigerant I believe I can get this problem corrected and be extremely cool in both of my cars.

Thanks Ryan