Aftermarket Fuel pump wiring

[1967KaiserM715]

I am trying to figure out how to wire in my fuel pump with a safety switch and an over-ride switch for priming the system, I am uploading a picture that shows how it is currently wired.

I have one issue right now that I do not know how to solve, and would like some input on this-When I flip my override switch the motor turns over-not a desirable outcome.

The other-which is minor, and should be solved by providing a constant power source, is the fail indicator light is not coming on.

EDIT: The oil pressure switch is Standard Motor Products PS64.

[bd]

Studying your diagram, it appears that the OPS terminals are as follows: "P" is the common (Com) contact, "S" is the normally closed (NC) contact and "I" is the normally open (NO) contact.  So, "P" connects to "S" when there is zero oil pressure, then switches to "I" as engine oil pressure builds. 

Move the OPS "S" terminal wire from the starter solenoid "S" terminal to the starter solenoid "R" (relay) terminal.  This will solve the problem of the stater cranking with the override (primer) switch.  If the starter solenoid doesn't have an "R" terminal, the following description elevates from "optional" to "mandatory."

As an 'option' for a starter solenoid with "R" terminal, but 'mandatory' if an "R" terminal doesn't exist, install a IN5404 (3 amp, 400 PIV) diode in the "white" wire between the OPS and the fuel pump relay with the cathode band oriented toward terminal "86" of the fuel pump relay.  The diode needs to be located between the OPS and the tie in point of the override switch.  Installed as an 'option' the diode will act as an isolator to prevent any possibility that the starter solenoid will power via the override switch in the instance that resistance develops in the factory solenoid circuit (purple wire) coming from the ignition switch.  When 'mandatory,' the diode will prevent the override switch from powering the "S" terminal of the solenoid.

Connect the indicator lamp relay terminal "30" to switched ignition.

Lastly, the override switch in your diagram has a ground connection.  I hope the ground is for a pilot light in the switch handle - otherwise disconnect the switch from ground.

If the foregoing discussion is unclear, let me know and I'll amend your diagram and repost it.

Someone else may suggest other possibilities.

[1967KaiserM715]

Perfectly clear, thanks.

Someone else mentioned using a DPDT switch, where  the OPS is on one side, override power is on the other side, throwing the switch disconnects one or the other. I will try this first as I have lots of switches to choose from, and easy access to more.

And ground for the switch is/was for a pilot lamp.


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[bd]

An on-momentary SPDT would accomplish the task, as well, where On = Crank/Run and Momentary = Prime (switch common to terminal 86 of the fuel pump relay, NC to OPS "P", and NO_mom to fused Ign/B+).

[hatzie]

You can terminate the wires at the starter solenoid to make miswiring the starter solenoid more difficult.  Install the correct inside diameter ring terminal. 
The S (Start) terminal from the ignition switch is a #8 machine screw and the R terminal should be a #10 machine screw. 

[Stewart G Griffin]

Have you seen this?

http://www.how-to-build-hotrods.com/electric-fuel-pump.html

[1967KaiserM715]

Have you seen this?

http://www.how-to-build-hotrods.com/electric-fuel-pump.html

That was the basis for my wiring, rather for the safety switch part.

So what I ended up doing was putting an insulated spade connector in the relay switch wire, so I can either connect the over ride switch, or the oil switch, but not both at the same time-so there is no worry of sending power where I don't want it.


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