Electrical hookup for Electric Fuel Pump

M

maxparplus

Member
I have installed an electric fuel pump, filter and regulator and replaced all the fuel lines in my '38 Ford Standard Coupe. I hooked up the electrical through the switched connection on the back of the steering column ignition switch. I get a one volt drop to the fuel pump and it will not run. When I hook up 6 volt battery direct to fuel pump it works fine. The ground is good but with this voltage drop it aint working. Can someone direct me how to hook up the electrical so I don't get the drop in voltage. I ran the electrical through a switch I mounted on the dash and the voltage at the input and output side of the switch is barely over 5 volts. The battery is fully charged to 6.4 volts. Thanks,

Max
 
Max, your hookup is a bad idea for several reasons. Never take power from the ignition for anything, your ignition can't afford to donate to charity. Hopefully you use the electric pump as a spare for use when your mechanical can't cut it, so run a separate lead from the hot side of your fuse block, and use a Normally Off toggle switch for safety. You sure don't want to leave the pump running after you park the car.
 
Max ... What is your email address and I'll send you photos of what I just did on my '40 set up. I'm traveling and will not be home until late tonight but I'll send when I get there.

Mike42
 
If you do what Alan suggested, you'll be happy with it. I have 3 electric fuel pumps (in 3 different cars). All used as a backup for priming & vapor lock situations. I used momentary toggle switches which are normally in the "off" positon. Good luck.

Pat
 
ford38v8 said:
Max, your hookup is a bad idea for several reasons. Never take power from the ignition for anything, your ignition can't afford to donate to charity. Hopefully you use the electric pump as a spare for use when your mechanical can't cut it, so run a separate lead from the hot side of your fuse block, and use a Normally Off toggle switch for safety. You sure don't want to leave the pump running after you park the car.
Click to expand...

Use a fuel pump relay.
 
I also used a relay but I use my fuel pump as the main pump. Also put a pressure switch on the oil pressure line. In case of an accident and/or the engine quitting the fuel pump will shut off automatically.
 
I installed an inertia switch off a later Ford product to shut off my pump in case of accident in case the engine doesn't shut off.

Most later Fords with electric pumps have inertia shut off switched. You can find them relatively cheap of ePay.
 
Messed with it for a few days, finally figured out the problem was a poor ground.
Switched to 1 gauge wire cleaned cross member and installed a clean ground and now it works off of the coil connection to the ignition switch so it's dead when switch is off. Also put in a dash switch for on/off and used a pressure regulator with a guage. It appears to work well. Thanks for the help.
Max
 
Just my two cents. # 10 wire is normally would be good for 30amps. With good connections and of course a short run, it's not necessary. #14 should be more than adequate. Good connections are the failure of any wiring.
 
maxparplus said:
"Now it works off of the coil connection to the ignition switch so it's dead when switch is off."
Max
Click to expand...

Max, your ignition switch doesn't have an another pole for when the switch is on? Not a good idea to take power from the ignition. Just my 1¢ worth.
 
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