Control Pressure Regulator
- Unplug connector at control pressure regulator. With voltmeter, check for 11.5 volts at wiring harness connector. On 1975-77 models, disconnect air sensor connector and positive wire at alternator (Volvo only).
- On 1978-79 Volvo, connect Test Relay (5170) to ignition coil. On 1978-79 Saab, connect jumper wires to fuel pump circuit and remove positive wire at alternator.
- On all models, connect ohmmeter between positive terminal on control pressure regulator and ground. If ohmmeter reads infinity, replace control pressure regulator.