1978-79 Volkswagen & 1979 Jaguar
- Remove auxiliary air regulator and connect an ohmmeter to both terminals of regulator. Resistance reading should be 30-33 ohms. Apply compressed air to regulator. Passage must be open while engine is cold.NOTE: If regulator resistance is correct, use test light to check voltage at regulator plug while engine is running. If no voltage, check double relay. Also check that starter solenoid wires on terminals No. 30 and 50 are not reversed.
- Connect battery voltage to both terminals. As temperature increases, opening in regulator should become smaller. If ohmmeter reading is incorrect or if regulator fails to close with voltage applied, replace auxiliary air regulator.