Ignition On_Starter On Relay

[dave w]

I'm adding fuel injection to an old car, that had points. The challenge I'm working with is the old car had used the "R" terminal on the starter to power the points coil when the car was starting. The old car has an ignition switch that has either "Ignition On" power or "Starter On" power.

I'm wondering if anyone has successfully used a relay wired like the diagram pictured below to provide both "on & start" power to the fuel injection?

Basically terminals 30 & 87a are normally closed, so when the ignition switch is in the "start" position terminal 87a will send power to terminal 30.

Basically terminal 30 will get power from terminal 87 when the ignition switch is in the "Run or On" position.

Relay specifications: https://www.waytekwire.com/item/75602/Hella-931680017-Mini-Relay-/

Thoughts or alternative solutions are greatly appreciated

dave w

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[MQQN28]

Dave

I have fuel injection on a flathead. I have just been burned by what you are trying to do. The steering column I have is a Mazda rx/4/3 with the ign switch and lock in the column. I was warned at the start the ign switch may not be able to handle the extra current. It didn't, and it gave up quietly and gave intermittent trouble. I was told to use a relay, I only did on the start cct.
Im not sure but it looks like you are trying to put the new ign cct through the relay contacts. This is a must if adding fuel injection.

I used a generic ign sw from NARVA 25A ign cct 15A acc cct. This seems to have solved my problems. Im still thinking to add the relay, one with 30/40A cct to be on the safe side.

The other problem can be sourcing a replacement for old ign switches. In my case if I could get one it was $200.00 as opposed to $45.00 for the Narva.

Part no Narva 64020 4 position ign sw

The answer is yes the relay cct should work ok.

[dave w]

Two relay diagram Ignition On _ Starter On. Normally Open 40A for both Ignition and Start.

dave w

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