A/C Solenoid Vacuum (SV) Valve (Standard Emissions)

1. A/C Solenoid Vacuum (SV) valve is mounted on firewall, to right of ignition coil. See Fig 1 . Install scan tester. Start and run engine. Turn A/C on and blower speed selector switch to any position except OFF. If engine speed increases slightly with A/C operation, A/C SV valve system is functioning normally.
2. If engine speed does not increase, backprobe A/C SV valve connector from cavity No. 2 to ground using a fused jumper. If engine speed increases, check for an open in Blue/Red wire. If wiring is okay, replace A/C amplifier. If engine speed does not increase, check for an open in Yellow wire. If wiring is okay, replace A/C SV valve.

Fig 1: Identifying A/C SV Valve (Standard Emissions)

Courtesy of GENERAL MOTORS CORP.