Date: Wed, 07 Jan 1998 07:29:44 GMT From: Ywan Mason <ymasonnopsamsouth.net> Subject: Re: need Air compressor, time to convert?
Another thing, if you get a 'kit' for the conversion, stick with the original pressure switch if it turns on the fans when a certain pressure is reached. On a 900, this doesn't apply, as the cooling fans are controlled by temperature and relays regardless of the ac system pressure. The switch on a 900 only prevents the compressor from engaging if there is insufficient refrigerant. On a 9000 on the other hand the fan is controlled by system pressure and the old switch turns the fan on at a lower pressure. The result is reduced high side pressures, increased component life, less wear/strain on the engine and cooler interior temps. Our shop has done many conversions this way and the difference in cooling between the R-12 and R-134a systems is negligible, in fact the R-134a may be a little better if the fan switch is left alone and the proper amount of 134 is used along with proper techniques. The secret is to keep the high side pressures as low as possible.