Main Relay (Computer/Fuel System): Testing and Inspection

Control Relay Location:

Control Relay System:

To test the Control Relay, located in the passenger compartment (under dash, passenger side), Proceed as follows.

CAUTION: When applying battery voltage directly, make sure that it is applied to the correct terminal. Otherwise, the relay could be damaged.
NOTE: Failure of the control relay could interrupt power supply to the fuel pump, injectors and ECU, resulting in start failure.
NOTE: Confirm circuit tester polarity before checking continuity.

1. In the following order check continuity between the specified terminals, as instructed.

To test coils L1 and L2:
Check terminals 3 and 4: should be non-conductive (infinite ohm).
Check terminals 3 and 9: should be conductive (Approx. 95 ohm).
Check terminals 10 and 7: should be conductive (Approx. 35 ohm).

Coil L1 And L2 Test Hook-up:

Apply positive power to terminal 7 with negative power applied to terminal 10.
Check terminals 3 and 4: should be conductive (0 ohm).
Remove power.

To test coil L3:
Check terminals 1 and 6, should be non-conductive (infinite ohm).
Check terminals 8(+) and 6(-), should be non-conductive (infinite ohm).
Check terminals 8(-) and 6(+), should be conductive (0 ohm).

Coil L3 Test Hook-up:

Apply positive power to terminal 6 with negative power applied to terminal 8.
Check terminals 1 and 6, should be conductive (0 ohm)
Remove power.

Test between each terminal and the case: All terminals should be non-conductive (infinite ohm).


2. If the results are not satisfactory, replace the control relay.