<VV> Oil pressure switch... Electric fuel pump wiring

[Dennis & Debbie PLEAU]

P is power, I normally open, P is normally closed.   I've used this switch a 
few times and have done it differently from what you are.  I connect the P 
terminal to ground.  The S terminal to the idiot light and the I terminal to 
the ground wire of the fuel pump and then feed the positive side of the pump 
off the fuse block.  I always use a switched terminal on the fuse block, but 
it really isn't necessary.

With no oil pressure the P and I connection are connected, and the light is 
on, as soon as you get pressure the P and S terminal are connected and the 
fuel pump turns on.

The downside of this set up is if the carbs are dry and the engine doesn't 
start, it takes a while to get fuel pressure.  I have a jumper wire in the 
glove box turn so I can ground the wire to the S terminal, but I usually 
crank the car until the oil pressure light goes out and I hear the fuel pump 
start and let it set a while until the pump turns off and then it has enough 
fuel in the carbs to start.  This works well when the engine is cold because 
the oil pressure holds a while after you quit cranking and I can usually get 
enough fuel in the carbs I one try.

A 10 Amp fuse would be plenty big to run a fuel pump

dp





>From: Cash Case <cash.case at sbcglobal.net>
>To: VirtualVairs Vairs <virtualvairs at corvair.org>
>CC: Cash Case <cash.case at sbcglobal.net>
>Subject: <VV> Oil pressure switch... Electric fuel pump wiring
>Date: Sat, 7 Apr 2007 15:57:47 -0500
>
>Hey guys. I have a couple of questions. Last week I ask for info on
>wiring up an electric fuel pump. I got lots of replies. Thank you for
>all of them.
>
>The route I'm going is to use a three prong oil pressure switch (OPS)
>on the ground wire and connect the positive wire up to a battery hot
>wire [dreaded RED platic thingy] with a fuse. The OPS is a 70's style
>Vega/Monza model (Thanks Donald Broadhead and Matt Nall)
>
>The OPS I picked up at NAPA auto parts [part number ECH OP6610] has
>three terminals. Two that oppose each other and one between them that
>goes out to the side. The center one gets the existing idiot light
>wire. The other two complete the ground circuit for the fuel pump.
>One connected to the fuel pump and the other grounded.
>
>My question is this: There are letters on these terminals. On the two
>that oppose each other one has an 'I' and the other has a 'P'. The
>other one has the letter 'S' on it.
>What do these letters mean? Any ideas?
>
>Also, can anyone recommend a fuse size for this application?
>-C
>
>Cash Case
>cash.case at sbcglobal.net
>www.cashcase.us