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judycarlyn's avatar
judycarlyn
Explorer
Jul 12, 2014

Losing engine A/C upon Acceleration

I am having Engine A/C problems on my class A motor home Rexhall Aerbus. Stops cooling at higher RPMs and returns to cool air upon on deceleration. The following issues have been checked and resolved:
* New evaporator coil box
* New dryer
* New heater control valve
Two ounces of oil was put in and it was charged up to spec.
The vacuum system was checked thoroughly and there are no leaks, the outside air door is working properly, (no heater duct issue). Cools to about 55 deg at idle and stops blowing cold ait at about 2100 RPMs. Cold air returns as RPMs come down. Could we have a bad compressor relay? Any suggestions or help would be greatly appreciated.

Thank you, Bob and Judy

12 Replies

  • Vacuum problem. Shutters in the AC/heater duct work are controlled by the engine vacuum. Look for a bad rubber vacuum hose or low engine vacuum.

    -Tom, W3TLN
  • Most dash AC compressors will cut out during hard acceleration. If you accelerate slowly up to cruising speed does the AC keep cooling?