Automotive Air Conditioning Information Forum (Archives)

Winder on Thu August 14, 2014 9:51 PM

Year: 1986
Make: Chevt
Model: c10
Engine Size: 350
Refrigerant Type: r134a
Ambient Temp: 85
Pressure Low: 32
Pressure High: 175
Country of Origin: United States

Truck cools real good. It has vent temps at 40-37 degrees going down the road. I have the cycling switch adjusted to 25psi. I have tried 2 other switches. But going down the road the compressor cuts on and off quite a bit. At idle it doesn't cycle. The compressor is a NEW r4 compressor fitted for 134a. As I could remember the other R4 compressor never cycled- ran all the time. Maybe I am overly worried???

Dougflas on Thu August 14, 2014 10:13 PM

May be slightly low on charge. Measure the inoput and output of the evap. Output should be slightly colder than input. Open windows and doors. Run engine at 1500 for 10 minutes. See if it cycles and at what pressures. You may be only a few oz low.