Prelude L4-1958cc DOHC (1989)
Main Relay (Computer/Fuel System): Testing and Inspection
Main Relay Harness Test
1.
Keep the ignition switch in the OFF position.
2.
Disconnect the main relay electrical connector.
3.
Check for continuity between the BLACK wire, Pin (2), in the connector and body ground.
Fig. 55 Main Relay Harness Test (pins 2 and 1)
Fig. 56 Main Relay Harness Test (pins 2 and 5)
4.
Attach the positive probe of the voltmeter to the YELLOW/BLUE wire, pin (1), and the negative probe to the BLACK wire, pin (2).
a. Battery should be available.
b. If there is no voltage, check the wiring between the battery and the main relay as well as the EFI ECU fuse (10A) in the under-hood relay box.
5.
Attach the positive probe of the voltmeter to the BLACK/YELLOW wire, pin (5), and the negative probe to the BLACK wire, pin (2).
6.
Turn the ignition switch ON.
a. Battery voltage should be available.
b. If there is no voltage, check the wiring from the ignition switch and the main relay as well as the #12 (10A) fuse.
Fig. 57 Main Relay Harness Test (pins 2 and 4)
