VALVE GP-CONTROL 4T0436 - Caterpillar

Check Electrical Connections
Illustration 1 g01519961
Typical schematic of a circuit for a compressor
Verify that the air conditioning clutch engages when the machine is turned on and the air conditioning switch is turned to "ON". An audible click should be heard after the air conditioning switch is turned on. This audible click should not occur until 15 to 30 seconds after the air conditioning is turned on.
Ensure that the connectors are tightly connected. Also check that the connectors are secure at the following locations:
Compressor protection module
Low-pressure switch
High-pressure switch
Coil for the clutch for the air conditioning compressor
Clean the connectors of the circuit. Refer to Illustration 1.Check For Input Signal From Air Conditioning Pressure Switches And The Thermostat Switch
The compressor protection module should prevent engagement of the clutch for an unlimited period if the low-pressure switch, the high-pressure switch, or the thermostat switch is open. Perform the following tests:
Measure the resistance between pin 1 and pin 2. The resistance should be below 10 ohms. If the resistance is above 10 ohms, perform step 1.a and step 1.b.
Test for a proper ground to