Ignition Switch Question ... 12v while cranking

[55mike]

I'm installing a Sniper fuel injection system on my 55. The main power (positive/negative) are hooked directly to the battery.

There is also a 12v "trigger" wire that is attached via the fuse-block that MUST have 12v while cranking and when in the run position.

My testing indicates no 12v when cranking on my fuse block. I have 12v when in run.. no problem.. it's the 12v when cranking/starting that I'm challenged with.

I've been given solutions such as a separate circuit utilizing a relay, which is not an option I really want to do.

I understand a simple jumper wire can be installed at the back of the ignition switch between #1 and #2 terminals, which will then provide 12v and both "run" and "Crank" positions of the switch. Has anyone here done this modification? Did it work ok?
Thanks
Mike

[Rick_L]

Yes, jumper the IGN1 and IGN2 terminals. It's been done forever when using electronic ignition and needing to eliminate the ballast resistor. Works equally well for an EFI retrofit. This applies only to 55-56 cars.

[55mike]

Thanks Rick!! That’s the answer I’m hoping for…

[55mike]

RickL … ok I did a temp jumper wire between ign 1 and ign 2 on the base of the terminal . Turn the key to “on” (not start) and the engine cranks…. Yikes! Not what it should do. I double checked the markings on the switch and am sure I’m jumping #1 with #2.
What am I doing wrong??

[chevynut]

ok I did a temp jumper wire between ign 1 and ign 2 on the base of the terminal . Turn the key to “on” (not start) and the engine cranks…. Yikes! Not what it should do. I double checked the markings on the switch and am sure I’m jumping #1 with #2.
What am I doing wrong??

There are "IGN1", "IGN2", "ACC", "BAT" and "SOL" terminals on the stock switch. The IGN1 and ACC are only supposed to be hot in the "run" mode. SOL and IGN2 are hot in the start mode. SOL and IGN2 are connected together during cranking, so if you jumpered IGN1 to IGN2 it would crank as soon as you turn on the key.

I used a diode on mine between IGN1 and IGN2 to prevent this.

[55mike]

I’ll check again

[55mike]

Yes sir. I double-dog checked. I jumped ign 1 to ign 2 …. I’ve never wired a diode in my life. Fact is wiring is my least favorite thing to do.
Is there an alternative?
If not …… what sort of diode?

[55mike]

Did some googling on diodes, appears an “in line” would work… still not sure when end would be + and which would be - in relation to #1 and 2 terminals…

[chevynut]

I researched the stock ignition switch thoroughly and made notes on what was connected to what in all positions. Unfortunately all my notes are at home and I’m in Montana this week.

Based on the way I think the stock ignition switch works I’m pretty sure yours is defective. It looks like IGN2 and SOL are always shorted together. They’re only supposed to be shorted together through the BAT terminal while cranking. Unplug everything and check if they’re shorted.

You can fix it without a new ignition switch by using a relay and a small diode if you want to. The nice thing about a relay is it takes the load off the ignition switch. I used one on my SOL terminal too.

[55mike]

Thanks for the responses and research. I think I’ll call American AutoWire next week and see if they can also shed some light. They sell a universal switch that might work, or perhaps I’ll get a new stock-style switch and jump #1 and #2 terminals. As a side note the old switch works just fine, it’s getting that 12v on cranking that’s kicking my tail.