73-79 Body swap, NSS trouble, ignition problems...
 

I just put a 73 cab on to my 79 frame. I've wired in the electronic ignition box just as described in this thread https://www.ford-trucks.com/forums/3...-ignition.html
and it appears to be working (red wire has power when key is 'on' and white gets power while motor is cranking). My ignition coil is getting no power when the motor cranks though. The green to the coil runs to the ignition box, and the red wire goes to the quick connect that leads to the neutral safety switch on the side of the trans.
This quick connect has 4 wires going to the trans, and three coming out on the other side. One to the coil +, another that is a bare wire that has power when the key is on, and the third isn't showing power, but has a connection that looks like the right angle rubber connection that plugs into the I or S terminals on the solenoid. I don't know what these two wires go to, and the wiring diagram in my Chiltons doesn't show these.

I found the red wire that connected to the coil on the 73, and plugged it in, and it shows power to the coil while cranking, but still no firing.

I think it's able to crank because the NSS on the 73 column is still working, but the 79 NSS isn't wired in fully... Any suggestions on where to begin?:-huh

The red from the module should not go to the neutral safety switch. The 73 cab should have the ignition switch on the instrument panel correct? And you have that all wired in? If so, the red module wire should go in directly to the back of the ignition switch. I think your switch will have a pink wire. This is the resistance wire that feeds the coil +. Hook the red module wire right at the ignition switch at the pink wire terminal.

The pink wire runs out into the engine compartment, and goes to a splice (I am looking at a 1972 diagram, I hope it's the same) where it joins to a brown wire and a red/green wire. The brown wire is supposed to be hooked to the "i" terminal of the starter solenoid. After this splice, the wire is red/green and goes to the coil +. You need to have all this original wiring hooked up for it work correctly.

The Red from the module isn't going to the NSS. The red from the coil is.
I ran a jumper from the I on the solenoid to the + on the coil, and checked everything with the test light, and everything seems to be getting power. I'll mess with the actual wiring tomorrow (no jumpers!) and get it all dialed in, and try to get it fired up. I'll look into what you listed and double check which wires I spliced into. The red module wire was spliced into a wire in the ignition switch that only had power when the key was on, and the white was spliced into the wire that went into the S on the solenoid, but at the ignition switch.

Just to add a bit to the confusion. My 74 crew with a 360 will crank and not fire. If I jump the coil directly to the positive on the battery it will fire every time. I believe there is a ballast resistor in-line somewhere in the wiring, which is causing the non-fire issue. I was looking at my wiring last night and the colors are all as Franklin2 says - red w/ green stipe which turns into a small brown (16 ga?) and a 10 or 12 ga. pink. These lead back towards the firewall, and I'm sure through it - although I got lazy and quit working, so I'm not 100% positive where they lead.

Franklin2 - does the diagram you have show a resistor in there somewhere? I'm pretty sure my problem is a resistor and ihate's may be the same. Taylor - have you tried jumping the coil directly to the battery to see if it will fire? Keep in mind the truck will not turn off with the key after this - so be ready to pull the jumper wire when you want to turn the motor off...

I spliced the Red wire for the module into the pair of pink(red?)/yellow stripe wires that go into one slot, I'll follow those back and see what they go to. I followed the brown wire up under the dash, but haven't unwrapped it to the end yet.

I ran a direct jumper to the coil, and it seems to be trying to fire (well, backfiring out of the carb actually, so I'm sure I blew out the Holley :-banghead). I'll keep at it, and update as I go...

EDIT: The wire I spliced the module red wire into turns into the fat pink wire with 'resistor - do not cut' printed on it, followed that back, connected to a plug with the oil and temp hookups, and the red wire that was connected to the coil + on the 360, hooked it all up, and it's cranking and backfiring like crazy, but at least it's trying to fire. Thanks for the input guys, anything else comes up, I'll post it here...

Well, everything is wired in properly, but it's still not starting. The coil and dizzy are getting power, and I've checked a couple of times to make sure that the dizzy is in the right way. It's just strange, because if I crank it too far advanced, the starter slows down and acts like it's building up pressure. Maybe a tooth or so off? I've rotated the dizzy on this thing plenty of times before, and have never had this happen...

Messed with the dizzy, and found out the battery was just under 12v. Took most of the day, but got it to fire up and idle great!

Thanks once again for your help Franklin2, you are an asset to this site (and my vehicles!)

As you probably have already read from one of the previous posts, the pink wire is the resistor. It's a special length of resistance wire. It leads from the ignition switch to the splice with the red/green and brown wires.

Yup - got that from Taylor's eariler post. I didn't see the text on the pink wire, but now I know that's the one I get to yank out and replace with a normal wire...

luckily I saw Taylor's link to this thread or I would have followed that pink wire looking for an in-line resistor. His problems helped sove mine!

Thanks guys.

Resistor Wire
 

There were two different resistor wires used in the 1970's.

COLF-12250-A .. Resistor Wire (Motorcraft DY-37) Most commonly used 1960/72.

61.50" long / color coded Pink / 1.30 to 1.40 ohms resistance / #16 gauge wire.
----------------------------------------------------------------------------
D7AZ-12250-A .. Resistor Wire (Motorcraft DY-213) Usually used 1973 and later.

49" long / color coded Red with Green Stripes (Red may fade to Pink) / 1.30 to 1.40 ohms resistance / #16 gauge wire.
------------------------------------------------------------------------------------------------------------------
Neither of these wires are available from Ford * any longer. NAPA (prolly others) can cross the Motorcraft # over to another brand.

* Nine US Ford dealers show having stock of COLF-12250-A / Don Sanderson Ford in Glendale AZ shows 5.

Four US Ford dealers show one each of D7AZ-12250-A. >

Wahlstrom Ford in Chadron NE / Gaylen S. Wright Ford in Heber City UT / Clevenger Ford in Porterville CA / Domino Ford in Park Rapids MN.

Thanks for the info, but I'm not putting a resistor wire back in the thing. The resistor is (I believe) the reason it is not starting. Therefore I am just replacing the resistor wire with a "normal" wire. New coils have built in resistors anyways - so no reason for the resistor wire.

Not always true. Some coils do have resistors built into them, but that is not what you want. If you do that, then you will not have the start resistor bypass, and starting in cold weather will be difficult. You can yank the resistor wire out, or bypass it, but you need to install a large white resistor you can buy from the store. Usually they will have one for a chrysler, and it will work ok. The resistor is there for a reason, and if you eliminate it, you will find yourself buying numerous ignition modules and coils, as they will run very hot and burn up. The resistor is not one of those "don't need it, just and emissions thing" type components. It's a very important part of the ignition system.

When you install the chrysler type resistor, make sure the brown wire from the solenoid is hooked on the coil side of the resistor. The brown wire is the start bypass.

Thanks for the input but from talking to a couple very trusted mechanics I am not worried about eliminating the resistor wire. It may be part of the designed system - but it sure seems like a CRAPPY, old design as it doesn't work worth a damn right now:)

Cold starting is NOT an issue as 40* is the very coldest we see and I wouldn't be driving the crew on those days anyways. That and I am doing the Cummins swap soon, so the truck will really only be driven maybe 10-15 times (yeah right - maybe 3) before the entire wiring harness gets dumped for the dodge harness anyways.