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Wires on a fuel pump

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jaegzie

jaegzie

Jedi Hopeful
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I searched briefly and couldnt find what I was looking for.

First the car is a 59 and I am putting a 1275 in it. I have a 64 wiring harness but right now I am just hooking p what I need so I can get it running. Not sure if I will go positive or negative ground, probably negative, but anyway...

I have a fuel pump out of a Sprite, year unknown, found in a box of carbs. It is the same as the one in the 69. My wuestion is without haveing to lift up my 69 because it is still in storage, is there only one electrical wire that runs to this, being a positive to the threaded post and then just hooking up the grounded wire? or is there something else. I could just try hooking it up and seeing if it pumps but I dont want to burn anything out as it would take a whole day trying to find the box of fuel pumps in my dads parts. TIA.
 
'69 Sprites were negative ground. I do know the fuel pump in Bugsy my '68 will not work when hooked up as Positive Ground but when hooked up that way by the DPO did not damage the pump. In fact I got a great buy on the car as he could not figure out how to get it to run and stay running. He had hooked the battery up as a Positive Ground car after he transplanted a 1098 from a 66 + Ground Spridget. A week of head scratching after I purchased the car and I had that Eureka moment, flipped the battery around, fuel pump went tick, tick, and the engine fired off and ran all on it's own. Of course YMMV.
 
Thanks for replying, i am hooking the car up to get it to fire with negative goround first then I may use the wiring harness an do through to make everything positive ground, I havent decided yet. My first post was kind of confusing after I reread it.

What I am looking for is does the power just go to the threaded post on the back of the pump? and the wire that is connected to it go to ground.

Also, this pump has been in a box for probably 20+ years, so should I go through it or lube anything up first? Thanks, I just do not want to burn this up, that is usually my luck. TIA
 
Sounds like singe wire pump. Positive to the wire and negative is achieved by grounding to the chassis. I'd hook to a 12 VDC souce for a second and make sure it spins up. These things are cooled by gasoline so you could set it up to pump some gas from one caontainer to another with some hoses. I'm sure a quick spin up to make sure it powers up won't hurt anything. Again YMMV.
 
Don't feel bad. I recently had to ask what that stood for also.

Over the years SU used diodes or capacitors in parallel to the points in the fuel pump to protect the contacts. Sometimes nothing was fitted. When the diode or capacitor is fitted you can change the polarity of the pump by reversing the component fitted in parallel to the points.

It's not my place to offer the service of others, but I'll bet if you took the cap off your SU pump and photographed what's there Dave DuBois could probably tell you in an instant what polarity the pump is and how to convert it if necessary.
 
The 69 fuel pump will work either + or - grd.
If the pump has the plastic nipples, it is generally either ground.
Later pumps that had threaded nipples usually have the diode and are - grd ONLY.
This started sometime in the 70s.
Adding a good clean ground wire to any SU fuel pump makes a world of difference.
 
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