Switch that interrupts the ground circuit

plumkrazee70 said

I want to put in a anti theft device on the ground circuit of my fuel pump. Can I just get a two prong switch, and wire it in series of the ground circuit?

My thinking is when it is off, the circuit won't be completed, therefore no power to pump, flip it on and circuit completed.

Am I thinking about this correctly?

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Krazee

That will "work".

HOWEVER, here is why I wouldn't do it this way. In this plan, you will be running quite a few amps through the switch, and the quality of your switch will determine how good of a ground you will have for your fuel pump. If you are using a really-good high amp switch for this, then you will probably be fine in the long run. If you are using, say, a cheap lit rocker switch from the racks of your local O'really's, then in a measure of months or years, you may be chasing after intermittant or inoperative fuel pump issues! Possible symptoms--the switch is hot to the touch, the plastic in the back melted, etc.

I don't know what pump your running or how many amps it draws, but I am entirely with RedFish on the best way to do this. Interrupt the low-current side of a fuel pump relay (the coil).

Are you using a fuel pump relay?

David