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75gmck25 · 11-22-2007, 07:10 PM

According to the repair manual for my '75 GMC the compressor will always be on in defrost mode. It will cycle off when the evaporator temp sensor (or outside air) reaches 35 degrees.

My original A/C controls were marked in one section as Economy Mode, since the compressor or will not cycle on in those positions (I think it was the positions for Floor only or Vent only).

Bruce

11-22-2007, 07:10 PM	#8
75gmck25 Registered User Join Date: Nov 2007 Location: San Antonio, TX Posts: 28	Re: Compressor cycles with defrost? According to the repair manual for my '75 GMC the compressor will always be on in defrost mode. It will cycle off when the evaporator temp sensor (or outside air) reaches 35 degrees. My original A/C controls were marked in one section as Economy Mode, since the compressor or will not cycle on in those positions (I think it was the positions for Floor only or Vent only). Bruce