Fuel Pump Relay: Description and Operation

Fig. 16 Relay diagram. Six Pin Relay:

Six Pin relay

With ignition on, current is supplied to the pull-in coil which is grounded through the transistorized circuit whenever the starter is operating (50) or the air sensor contact (31B) is open during normal running. The pull-in coil completes the circuit between battery terminal 30 and the fuel pump via the 16 amp fuse on top of the pump relay, Fig. 16. To run pump with engine off for testing purposes, remove air sensor electrical connector with ignition on.

Fig. 17 Relay diagram. Five Pin Relay:

Five Pin Relay

With ignition on, current is supplied to the pull-in coil which is grounded through the transistorized circuit whenever impulses are received from the ignition coil during starting or normal running, Fig. 17. To run pump with engine off for testing purposes, remove relay and bridge relay board terminals L13 and L14 with jumper wire or accessory US 4480.