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Positive ground fuel pump

PostPosted: Mon May 19, 2008 6:45 am
by Mark McNaught
I converted my frogeye to a 1275, and have fried two electric pumps not realizing that they needed to be positive ground. I have an SU fuel pump to perhaps install, but I have no idea whether it's - or + ground. There is nothing indicated on the housing. How can you tell? Can it be easily changed? Even if it is a - ground pump, can it be used in a + ground car if it is completely isolated?

Re: Positive ground fuel pump

PostPosted: Thu May 22, 2008 8:51 pm
by spritenut
Most, if not all of the Sprite SU fuel pumps work either pos or neg ground.
If you pull off the black top cap and do NOT see a diode, it works either way.
Most new or aftermarket pumps are neg ground.
I have taken a positive ground car and switched it to negative ground and never touched the fuel pump.
If you SU has the 2 plastic nipples secured by a round ring with 2 screws, it is the early type and can be grounded either way.