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Fuel pump relay schematic...

Posted: Sun May 27, 2018 5:07 pm
by ecksrash
I need to add a relay for my electric fuel pump. I want to use a 30/35 amp relay to keep it safe. I need a schematic that will not use the generator light or oil pressure to open the circuit. Thanks

Re: Fuel pump relay schematic...

Posted: Sun May 27, 2018 10:35 pm
by sideshow
I'm not following the question...you seem to be asking how to hook up a relay without a point?
So how do you plan on triggering it? For the record I like the Ford inertia switch used w or w/o a relay (it doesn't require one)

Re: Fuel pump relay schematic...

Posted: Mon May 28, 2018 4:44 pm
by ecksrash
I'm not real good with electrical circuitry. I currently have my electric fuel pump wired directly to the ignition switch 12V and then to ground. I want to lessen the load on the ignition switch and think that adding a relay will be a good idea. I've seen a few schematics that use a single relay and some that use 2 relays and a normally open switch to prime the pump.

Re: Fuel pump relay schematic...

Posted: Wed May 30, 2018 5:09 pm
by Kafer_Mike
Like this?

Re: Fuel pump relay schematic...

Posted: Fri Jun 01, 2018 8:15 am
by Dale M.
Use KISS (Keep It Simple Stupid) principle...

http://revolutionelectronics.com/Fuel_Pump.html

OR....
fuel_pump_relay.jpg
But it has to be the 321.906.059C relay, not just any off the shelf relay...

Or did you want plain relay with no safety controls...

Dale

Re: Fuel pump relay schematic...

Posted: Sat Jun 02, 2018 7:37 am
by GS guy
One note about wiring through the oil pressure switch. Years ago I did that with a CB electric pump conversion, feeding a mild dual Kadron 1600. It idled very nicely around 600rpm. I was getting some kind of interference in the radio at idle, and eventually realized the idle oil pressure was right at the idiot light sensor switching point, so it was rapidly switching the relay and pump on/off. This was a stock sensor which I think switched around 10psi? I had to raise the idle speed a little to get the pressure out of this range. YMMV.