Ranger 4WD V6-3.0L VIN U (1997)
System Relay: Testing and Inspection
RELAY COMPONENT TEST
Testing of an ISO relay can be accomplished through the use of three No.10 (or larger gauge) jumper wires and a Rotunda 73 Digital Multimeter
105-R0051 or equivalent. Remove (unplug) the relay to be tested from the power distribution box, fuse junction panel or individual connector.
Mini ISO Relay
Using the multimeter, check for the continuity between terminal 85 and all other terminals. If resistance is 5 ohms or less between terminal 85 and
any other terminal, replace the relay. If 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 the multimeter set in 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
Using the multimeter, check for the continuity between terminal 2 and all other terminals. If resistance is 5 ohms or less between terminal 2 and
any other terminal, replace the relay. If 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 the multimeter set in 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.
