Hi Nordic, about the holley part... Found it on summit (thanks!), but can't find a wiring diagram. The description on summit seems to imply it has a relay built in, and you wire it to your solenoid and +12, and voila, you have power to your fuel pump when either the starter is pressed or you have oil pressure. Your post says you use it to trigger an external relay. Does that mean the part is actually just an spdt switch (used for engine alarm + fuel shutoff)? Just looking for clarity on what the three terminals are for.

I used it just for the fuel pump.It has a normally open and a normally closed wiring tab on it.I used the nomally open switch and tapped into the hot on the coil.I then wired it to a relay for the pumps that is wired directly to the battery.The switch is rated to run full current for the pump but I wanted direct power from the battery and did not want to pull high amps off the coil.So I have it as just a switch for the relay.The third terminal I just left,not being used but could trigger a light on the dash if you want.


Nordic95

Thanks! Also got this from summit for anyone interested.

http://static.summitracing.com/globa.../sum-g1438.pdf

Check out figure 3.
http://static.summitracing.com/globa...s/maa-4110.pdf

Gary

Very cool! That's exactly what I was looking for! I'd rather have a tee for the alarm switch than have the wiring for an external relay. I think the current draw issue on the ignition circuit can be avoided by just hooking the normally open terminal to the battery, so the pump is either running off the battery or the starter relay. Awesome!

Just wondering if anyone has had experience with this pressure switch, holly part hly-12-810. I tried to hook mine up over the weekend. The normally closed side of the switch opens when the oil pressure come up, but the normally open side of the switch doesn't close. I have 40psi, tried with and without a tee in place. I bought two of these switches and both behae the same way. Anyone else have different/better results?
BTW, found out summit also has a different switch, sum-g1438, to provide a fuel pump shutoff. Anyone tried that one?
Thanks!

NAPA also has a switch that will work...~$10 I added a T to the oil pressure sender. Don't have the part # with me but will try to find it tonight. I did have to run the + from the battery...Shocked me the first time I turned off the engine and heard the pumps running till the oil pressure bled down.

let us know the napa pn when you can, thx, rm

It is an ECHLIN Part Number...ECH OP6611. Got electric fuel pumps from Jerrys. The pumps had a wireing diagram including this part as the safety shutoff switch. If your in Tampa, the DC had them in stock so the local NAPA stores can get them in a few hours.

I was a little worried about the current through the swicth but no failures so far. I may re-run the source through a relay and add a switch / breaker on the dash. Its setup now to energize while cranking the starter and powered direct from the battery w / oil pressure while running.

another supplier is Murphy, they have oil and temp guages with cutouts to protect the motors I have used these for years in many different applications.