A/C High Side Pressure Too High
Thread Starter
Intermediate
Joined: Aug 2001
Posts: 31
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From: Houston TX
A/C High Side Pressure Too High
Could someone confirm that the primary cooling fan should come on when the A/C compressor is engaged. Last summer the A/C worked fine as long as the car was moving but seemed to cut out intermittently in traffic. I finally got around to putting a set of gauges on it and my high side pressure gradually builds to over 350 psi on a 70 deg day (should be 150-160 psi). The fan was not running when the compressor was engaged but does eventually come on when the engine coolant temp reached about 230 so I know the fan is OK. I suspect I'm just not getting any cooling air across the condensor. Any A/C guys out there that can advise? Oh yeah, it is the original '90 R-12 system
Drifting
Joined: Dec 2000
Posts: 1,733
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From: Sarasota FL
Re: A/C High Side Pressure Too High (90 KOTH)
Your hi-side pressure should never be that high. less than 200 is normal. Primary reasons for abnormal pressures are:
1-Over charge (the excess liquid R-12 builds up in the condenser. The normal level is no more than 1/4 full, the rest is gas and bubbles)
2-Poor air flow over the condenser (dirt or no fan)
I believe that one fan starts with the compressor and the other cycles on the temperature switch.
1-Over charge (the excess liquid R-12 builds up in the condenser. The normal level is no more than 1/4 full, the rest is gas and bubbles)
2-Poor air flow over the condenser (dirt or no fan)
I believe that one fan starts with the compressor and the other cycles on the temperature switch.
