1985 460 fuel relay

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Jan 30, 2008 | 08:57 PM

79man

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From: Southern Illinois

1985 460 fuel relay

My 1985 f350 460 fuel system is giving me a headache!! I can't get the electric fuel pump to work while cranking. It works once it builds up oil pressure just fine. So does that mean that my relays are bad?

Also, I read on here somewhere that the back post on the solenoid is what triggers the relay while cranking. Is that correct?

Jan 31, 2008 | 12:40 AM

Franklin2

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Yes, the fuel pump gets power directly from the starter solenoid while cranking.

Jan 31, 2008 | 01:02 AM

Piffery1

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From: Niceville, FL.

The light duty solenoid contact that powers the fuel pump in "Start" can go bad (mine did) so you can move the pump wire over to the big "Starter" terminal.

Jan 31, 2008 | 12:57 PM

79man

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I took that wire off and put power to it, but the fuel pump did not turn on. So does that go through the relays, or send power directly to the fuel pump?

Jan 31, 2008 | 04:07 PM

Piffery1

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With single tank it goes from the solenoid terminal to a blue (20 ga.) fuse link, then through a diode to the pump. With dual tanks it goes from solenoid, through the fuse link, a diode, through the tank selector relay, then to the selected pump. Either the fuse link or the diode could be open. Or the Pink/Black hash wire could be open between the diode and where "Run" wire is spliced in. Since it works in "Run" then the oil pressure switch, fuel pressure cutoff relay, inertia switch, resistance wire, tank selector relay (if used) and pump are all ok.