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electric fuel pump wiring help.

Posted: Wed Apr 14, 2010 11:14 am
by rixm37
Where is the best place in the wiring harness to tap for a switched lead for an electric fuel pump?

Posted: Wed Apr 14, 2010 3:40 pm
by ffr1910
dont have a tip for a stock harness for you, sorry. i would make sure that you install an oil pressure switch in a tee with the oil pressure indicator and run it to a relay to run your fuel pump. this way if you are in a wreck that knocks you out, the fuel pump wont add fuel to a possible fire. that is how i wired mine :) bill

Posted: Wed Apr 14, 2010 5:31 pm
by N1VSM
I tapped mine from an unused circuit breaker. The pumps don't pull that much current, but having it protected just in case something catastrophic happens is always a good idea. It is a good ideA to make sure you aren't tapping into a circuit that is already drawing lots of current -the added draw might be enough to trip a breaker, and Mr. Murphy implies that it will be at the worst possible time / place. I also put an in-line 5A fuse. Ask if you want more details.

Posted: Wed Apr 14, 2010 7:29 pm
by rixm37
Hey thanks guys, I am trying to find a location that is controlled by the ign switch that will handle the pump current draw. Yes I do have an inline fuse. An oil pressure switch is a good idea also.

electric fuel pump wiring

Posted: Sat Apr 17, 2010 12:00 pm
by wvcharlie
I am putting an electric fuel pump in also. Does anyone happen to have a part number for the oil pressure switch to use as a safety switch and where to get it ?

Posted: Sat Apr 17, 2010 1:12 pm
by ffr1910
charlie,

i do not have a part number for you on the one i used. what i did was go to napa and looked at their "book". i got one that had an 1/8th inch pipe thread and two push on terminals. i think it was rated at 5 or 10 psi. any psi is okay as long as the switch CLOSES below your idle oil pressure. dont worry about a part number, just go into napa or oreilly and take a look through their book with those specs in mind.

bill

fuel pump wireing

Posted: Sat Apr 17, 2010 2:20 pm
by rtkjmk
When I added a electric fuel pump to my m37 I used a momentary on switch and switch cover for my installation . I only use the electric fuel pump as a primer ,when the vehicle sits for a while . I was a little concerned about too much fuel pressure to use the electric pump all the time.

Posted: Sat Apr 17, 2010 5:29 pm
by ffr1910
i also did this with my installation, that is, wired it to a switch to use as a primer. i also wired the whole shebang into a 12v(my truck is 12v) relay that is actuated by both the oil press switch and the momentary switch.
bill

Electric fuel pump

Posted: Sun Apr 18, 2010 3:54 pm
by moose3d
I put in a seperate keyed switch to turn on the fuel pump. It also works as the antitheft system for the truck, it will on go as far as the fuel in the carb bowl will take them til it is out of fuel.

Oil Pressure Switch

Posted: Thu Apr 22, 2010 6:46 am
by N1VSM
I finally found the box!

I used a switch made by Hobbs. On the box is stamped "76575 (smudge) 4 NO" I think I bought it at NAPA. It is a 5 PSI switch, if I remember.

I also added a 60A zeener diode from my starter switch to run the pump while my foot is on the starter pedal. No priming, switch flipping, or momentary buttons for me! Oh, yeah, and it is all fused heavily.