Electric fuel pump question

[Vanspeed]

I picked up an electric fuel pump for my model t bodied a chassis. I bought it from macs. It said replacement for ford model a's, 6 volt. I got it and I am ready to install it but the directions say to wire it negative ground. Will this pump work with the stock positive ground electrical system?

[machine girl]

one time we had one like that pumped the fuel backwards try an air tex 8902 2.5-4 psi

[Vanspeed]

Why not just turn it around then?

[Vanspeed]

This is a carter 2-4 psi pump.

[Tom Wesenberg]

Is it a motor driven pump, or is it a solenoid type pulsing pump?

The ground polarity would matter on the motor driven pump, but shouldn't matter on the pulse type unless it has a diode across the contacts to keep the arcing to a minimum.

[Mike V. Florida]

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Try giving Mac's a call. I would think if it made no difference it would not mention polarity in the instructions.

[Vanspeed]

It does not appear to be a motor driven pump. I will try calling them.

[howie123]

Vanspeed, I have the same fuel pump on my Model A speedster. I remember having the same question after reading the instructions. I even contacted the manufacturer with no response. Bottom line, the car is positive ground so I hooked up the pump with positive to ground. It works well. I did try it without a regulator but the pressure was still too high. I got a Holley regulator and turned it down to about 1 psi. I've had no problems with the pump. Hope this helps. Howie

[Vanspeed]

Originally Posted by howie123

Vanspeed, I have the same fuel pump on my Model A speedster. I remember having the same question after reading the instructions. I even contacted the manufacturer with no response. Bottom line, the car is positive ground so I hooked up the pump with positive to ground. It works well. I did try it without a regulator but the pressure was still too high. I got a Holley regulator and turned it down to about 1 psi. I've had no problems with the pump. Hope this helps. Howie

That is good news, i have read somewhere that as long as it's isolated, it will work either way. Hope it does.

[CheaterBobber]

When wiring the fuel pump can you run the positive lead from pump to ignition switch?

Thanks

[Tom Wesenberg]

Originally Posted by CheaterBobber

When wiring the fuel pump can you run the positive lead from pump to ignition switch?

Thanks

No, the ignition switch is the ground side of the coil, so nothing should be connected to it.

[BILL WILLIAMSON]

Originally Posted by Tom Wesenberg

No, the ignition switch is the ground side of the coil, so nothing should be connected to it.

"Maybe" he has his switch set up as a "HOT" switch.
Bill W.

[denis4x4]

I have a couple of A's with electric fuel pumps and I have them wired through a switch so when I'm setting the timing or some such thing, I can turn the pump off.

[CheaterBobber]

Ignition cable and ground to other post. That's why I thought could run positive fuel pump to positive ignition cable.

Thoughts

[Vanspeed]

I got it working, I wired the positive side of the pump to the the chassis and ran the negative lead to a toggle switch on the dash, then from the toggle switch to the terminal box. It works well, you just have to remember to turn the toggle switch on which is no big deal to me. Very happy with it so far.