Fuel Pump Electrical Circuit, Testing - BMW 5251 Service Manual

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Fuel Tank and Fuel pump]
Remove fuel pump relay (arrow).
4
Connect relay socitet terminal 6 (redlviolet wire) to relay
socket terminal 2 (whitelblue wire) with a fused jumper wire.
After completing tests, remove jumper harness.
CA U T I O G
Relay locations may vary Use care when identifying relays
and making electrical checks at the fuse/relay panel. See
610
Electrical Component Locations for additional re-
lay information.
The fuel pump relay has a 1.5 m d red/violet wire at
terminal 6 in the relay socket. Terminal2 has a 2 . 5 m d
white/blue wire. See ELE Electrical Wiring Diagrams
for additional wiring information.
NOTE-
* The fuel pump will run as soon as the jumper wire Is at-
tached.
The jumper wire should be 1.5 m d (14 ga.) and include
an in-line fuse holder with a 15A fuse. To avoid fuse/relay
panel damage from repeated connecting and disconnect-
ing, also include a toggle switch in the jumper harness.
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If pump does not run with jumper installed, fault could be in
fuel pump, fuses F31 or F22 1 F54, or wiring to pump. Check
pump, fuses and its wiring as described below.
Fuel pump electrical circuit, testing
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The test given below assumes that the fuel pump relay circuit
is functioning correctly as described earlier. Access to the
pump is from below the rear seat bottom cushion.
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Remove rear seat lower cushion by lifting front edge off left
and right catches.