What color wires for stock ignition switch?

[Blue71]

Ok...worked on her again today and got it wired up and started. Everything seems to be hooked up correctly now. I got rid of the previous owners solid black wire from the starter(ST) to the switch, and instead used the factory red w/blue wire which was still hooked up to the "S" terminal too and followed factory red w/blue stripe wire from the "S" side of the solonoid in through the pass. side of the dash, under the dash, and back out of the drivers side of the firewall to the neutral safety switch that is normally used for automatics, but is still wired in anyway. I spliced into this wire and ran it as my start wire and hooked it to both of the red/ w blue striped wires on the factory pigtail. My only problem is that it doesn't start until you let off the key to the run position. This is exactly how the aftermarket switch performed too. Not sure why its still doing this. Any ideas?


(ACC) Old black/green on factory harness = black/green new factory pigtail

(BAT)Old yellow on factory harness = Yellow on factory pigtail

(IGN)Yellow wire (not sure original color of this wire, it was spliced where it comes thru firewall from coil old harness = Green/red and red/green

(ST) Red/ blue wire from starter = both red/ blue wires on factory pigtail


Lord I hope this makes sense Let me know why this baby starts only when you let off the key

Thanks,

Andy
Blue71

 

[Viperwolf1]

Where you at Viperwolf

Blue71

Sorry. I've been hunting and living in a tent in frigid NW Colorado for the last week and a half.

Sounds like you have it mostly figured out. The brown wire from the starter solenoid "I" terminal to the coil positive terminal will get it running during cranking.

 

[Blue71]

Sorry. I've been hunting and living in a tent in frigid NW Colorado for the last week and a half.

Sounds like you have it mostly figured out. The brown wire from the starter solenoid "I" terminal to the coil positive terminal will get it running during cranking.

What????Hunting in the fridged NW for a week and a half????? You sound like you really hated it Looks like you had a great time. Glad you made it back so you can thaw. Thanks for the diagrams.

Yeah...I think I about have it. So I think what your saying is....I need to trace my Brown wire from the "I" terminal, through the firewall and under the dash. I then need to either splice into it, or possibly find the loose end of it if its been cut, and tie it into where I have my wire from the coil+ wire and my red/green and green/red wires all connected to my factory switch. Hope that makes sense. Or could I just run a new dedicated wire from the "I" terminal through the firewall and straight to where my coil+ attaches behind the switch? Let me know if I am on the right track. Actually..what is the "I" terminals exact job?

Thanks again and glad your back...we were beginning to worry about ya

Andy
Blue71



Thanks,

Andy

 

[Viperwolf1]

What????Yeah...I think I about have it. So I think what your saying is....I need to trace my Brown wire from the "I" terminal, through the firewall and under the dash. I then need to either splice into it, or possibly find the loose end of it if its been cut, and tie it into where I have my wire from the coil+ wire and my red/green and green/red wires all connected to my factory switch. Hope that makes sense. Or could I just run a new dedicated wire from the "I" terminal through the firewall and straight to where my coil+ attaches behind the switch? Let me know if I am on the right track. Actually..what is the "I" terminals exact job?

I do appreciate you guy's concern and I just want to say the rumours of my incarceration are totally unfounded.

Yes. I'd rather trace out the existing wire to see where/why the electrons stop but you could run a new wire. The "I" terminal provides full cranking voltage (battery voltage available while the starter is cranking) to the coil to assist with startup. It basically bypasses the ignition resistor during starting only. Without the "I" terminal you could get the problem you see or it may not ignite the cylinders at all if your battery condition was just a little worse.

 

[Blue71]

Well, I gave it my best, but my best wasn't good enough:0 I spliced into the Brown wire that comes from the "I" Post and ran it over to my coil+ wire under the dash where it meets the switch. It didn't make a difference. Does that tell me anything? Let me know. I'm open for suggestions.

Thanks again guys,

Andy
Blue71

 

[DirtDonk]

Great pics Phil! The guy on the left has a deer head coming out of his fly, and the guy on the right's crotch is on fire.
Other than that, the antlers coming out of the head look is very suitable for the occasion. ;D

Hope you had a great time. Don't look any worse for the wear to my eyes. Must've been some good times in there somewhere, to offset the cold temps?

Paul

 

[DirtDonk]

...I got rid of the previous owners solid black wire from the starter(ST) to the switch, and instead used the factory red w/blue wire which was still hooked up to the "S" terminal too and followed factory red w/blue stripe wire from the "S" side of the solonoid in through the pass. side of the dash, under the dash, and back out of the drivers side of the firewall to the neutral safety switch that is normally used for automatics, but is still wired in anyway. I spliced into this wire and ran it as my start wire and hooked it to both of the red/ w blue striped wires on the factory pigtail.

That part about the two wires spliced together should be fine. Since you have two, that original pigtail may have been off of a '74 or later truck with Duraspark?

My only problem is that it doesn't start until you let off the key to the run position. This is exactly how the aftermarket switch performed too. Not sure why its still doing this. Any ideas?

Might be the way you have the Brown "I" wire hooked up. But not sure. Maybe it's only contributing to the problem, but is not the core issue.
It should still start, but the Brown wire should be hooked into the circuit AFTER the firewall, so that it bypasses the resistor wire. The way you have it hooked up, it's still passing through the resistor, so the coil is not seeing the full 12 volt jolt during start.

(ACC) Old black/green on factory harness = black/green new factory pigtail

(BAT)Old yellow on factory harness = Yellow on factory pigtail

(ST) Red/ blue wire from starter = both red/ blue wires on factory pigtail

Sounds good so far.

(IGN)Yellow wire (not sure original color of this wire, it was spliced where it comes thru firewall from coil old harness = Green/red and red/green

These two wires go to two different places. The Green w/red goes to the voltage regulator, and the Red w/green goes to the ignition coil.
So that last one is potentially the oddball, along with the Brown wire.
If the Red w/green was bypassed between the firewall and the switch (like it sounds), then you don't have a resistor wire in the loop anymore, and something's up with this circuit.
Something is causing the power to drop off that wire during "START" only. Once it's back to "ON", then power is getting to the coil.

Here's a quick test. I think you said you already did it before, but try it again with the new setup.
Run a jumper wire straight from the "I" terminal on the starter relay to the coil's positive side.
See if it starts like normal now.

Some other checks to perform, just for the heck of it, and to give you an excuse to drink some beer.
Check the switch and wires to make sure the Green w/red wire is getting power at START. Disconnect the Red w/blue wire from the starter relay and turn the switch to START to see if there is voltage at all at the coil wire.
Might not be, but we want to check anyway.

We're just trying to track down why there is no (or insufficient) juice getting to the coil during start.

Good luck.

paul

 

[Viperwolf1]

Well, I gave it my best, but my best wasn't good enough:0 I spliced into the Brown wire that comes from the "I" Post and ran it over to my coil+ wire under the dash where it meets the switch. It didn't make a difference. Does that tell me anything? Let me know. I'm open for suggestions.

Thanks again guys,

Andy
Blue71

Check for voltage on the "I" terminal with the wire off and ignition in START. Could be a bad solenoid.

 

[Viperwolf1]

Great pics Phil! The guy on the left has a deer head coming out of his fly, and the guy on the right's crotch is on fire.
Other than that, the antlers coming out of the head look is very suitable for the occasion. ;D

Hope you had a great time. Don't look any worse for the wear to my eyes. Must've been some good times in there somewhere, to offset the cold temps?

Paul

It took hours of prep to get the proper lighting conditions for that shot. I guess you didn't notice the CB hat.

 

[DirtDonk]

You might even try just disconnecting that "I" post altogether and try it that way as well.
Can't hurt to test it. My thinking is that, if it's a bad solenoid, it could actually be partially grounding that circuit. Which would also take all the fun out of the spark department while starting.

Paul

 

[DirtDonk]

Nope. didn't even see it. Never seen on in person anyway, so wasn't focused. Was too busy looking for Broncos and Jack-a-Lopes.

Paul

 

[Viperwolf1]

Nope. didn't even see it. Never seen on in person anyway, so wasn't focused. Was too busy looking for Broncos and Jack-a-Lopes.

Paul

But there is a Bronco on the hat...

 

[DirtDonk]

Yeah yeah yeah. Says you guys with young (and still functional) eyes!
My eyes, they don't see so good since I've been spending so much time staring at the computer screen looking for Bronco hats.
That's nice by the way (thanks for the enlargement!). Are they still available here or was that a limited-time deal?

Paul

 

[Viperwolf1]

Yeah yeah yeah. Says you guys with young (and still functional) eyes!
My eyes, they don't see so good since I've been spending so much time staring at the computer screen looking for Bronco hats.
That's nice by the way (thanks for the enlargement!). Are they still available here or was that a limited-time deal?

Paul

Still listed: http://classicbroncos.com/merchandise.shtml

Sorry for the hijack Blue.

 

[Blue71]

Alrighty.....worked on it a little today. I have 8.91 volts at the coil when the switch is in the run position and I get 12 volts when I turn the key to start it. That sound bout right? Re-arrainged a few wires and still doing the same thing. This '75 has electronic ignition so could there be something going on with it? Let me know

Thanks,

Blue71

 

[DirtDonk]

The voltage is correct at the coil at least. Now to make sure it's getting to all the other correct places.

There is always the possibility that something is amiss with the ignition control module, but you can test a few things pretty simply.

Rotate the engine so that one of the teeth on the stator are lined up with the magnetic pickup. Pull the coil wire out of the center of the distributor cap and lay it down next to a good ground, such as the engine (as far away from the module as you can). Loosen the distributor clamp, turn the key on, and twist the distributor back and forth a few degrees so that the pickup slides past the tooth.
Every time the two pass each other, you should get a nice healthy spark form the coil wire.

Paul