Operation CHARM: Car repair manuals for everyone.

Component Tests

Mini ISO Relay







Using 73 Digital Multimeter, check for the continuity between Terminal 85 and all other terminals. If the resistance is 5 ohms or less between Terminal 85 and any other terminal, replace the relay. If the resistance is greater than 5 ohms, continue with the test. Using two jumper wires, connect relay Terminals 86 and 30 directly to the positive battery terminal. Using 73 Digital Multimeter set in the volts position, check for voltage at Terminal 87A. If battery voltage is not indicated, replace the relay. If battery voltage is indicated, connect a third jumper wire to Terminal 85 and ground the jumper wire to a known good ground. Check for voltage at Terminal 87. If battery voltage is not indicated, replace the relay.

Micro ISO Relay


Terminals:






Using 73 Digital Multimeter, check for the continuity between Terminal 2 and all other terminals. If the resistance is 5 ohms or less between Terminal 2 and any other terminal, replace the relay. If the resistance is greater than 5 ohms, continue with the test. Using two jumper wires, connect relay Terminals 1 and 3 directly to the positive battery terminal. Using 73 Digital Multimeter set in the volts position, check for voltage at Terminal 4. If battery voltage is not indicated, replace the relay. If battery voltage is indicated, connect a third jumper wire to Terminal 2 and ground the jumper wire to a known good ground. Check for voltage at Terminal 5. If battery voltage is not indicated, replace the relay.