So the zf swap is complete, and now I need to figure out the wiring situation. I don't care about the NSS per se, but the reverse is a necessity and 4x4 light would be nice. I've found a ton of stuff regarding later E40D stuff, but nothing for an early 80's small block with a c6. Can anyone give me a quick and dirty "this is what you need, this is what you do with it"? I assume I'll need the plug that plugs somewhere on the truck, and either the connector for the zf? Anything y'all' have would be much appreciated!

 

4 spade round plug on the drivers side frame rail used to connect to the NSS. 2 wires are to enable starting, I just those after doing a swap. Other two are for reverse lights. I have a plug (for the reverse switch on the ZF5) on my shelf waiting for me to get around to wiring it up. I can give you the part number if you need it.

 

That part number would be awesome Sir! I think i found one at autozone for it, but a cross reference is always good. So the 4 spade is permenantly affixed in the vehicles wiring harness on the frame rail, Jump the two for the starting, and tie the other two into the ZF5 plug that goes into the transmission? Wiring is not my thing, so I want to make sure I understand completely before I screw something up.

 

NSS (Neutral Safety Switch) only used with A/T .. M/T uses a back up lamp switch.

See 15520 in parts catalog pic:

 

Awesome, thanks for the clarification Bill. I knew that, habit just got the best of me.

 

upon looking, I've come across a few different switches with that number; F5TZ-15520-B, 6S6Z-15520-A, 97FZ-15520-A.....

 

If you want to go junkyarding, you can get the complete harness for the zf. On my 89 I had the donor zf truck and my c6 automatic truck I was swapping into. I unplugged the harness underneath the brake booster, took it out and got the harness from the zf truck, plugged in all the switches, ran it up along the frame, and plugged it back in the same plug under the booster. Everything works. The zf harness even has the jumper to jump out the neutral safety switch, the manual trans doesn't use one, it uses a switch on the clutch pedal instead.

If you make your own harness, you will need to jump those two wires like the factory did or it won't crank over. They are both red/blue.

 

Original part number: C9TZ-15520-C has been replaced by: 6L5Z-15520-A (Motorcraft SW-6396).

'Course, I don't know what the trans came from, so the above (listed for 1980/89 F100/350 & Bronco all M/T (except 4 speed O/D) may not be correct.

 

Bill, the trans is an S42, which was all I told the guys at the trans shop when I bought a new one.

franklin, so the not cranking part is a direct result of plugging in the zf5?

 

Connector - RockAuto

 

So it's not cranking? Yes, there are two red/blue strip wires that went down to the neutral safety switch on the side of the automatic. If you do not twist these two wires together, you will not get any power to the starter solenoid over on the pass side fender.

 

I was just trying to clarify if this problem would arise solely after putting the switch on the trans. If this is the case,I will plan on jumping these wires when I install it. If I should be having this problem even with no switch installed then i will assume that my mechanic did this, because I have no issues starting at the moment.

 

Not sure what switch you are talking about. There is no neutral safety on the manual transmission. And yes, you would definitely have this problem when swapping to a manual, so safe to say your mechanic has already tied them together.

 

im referring to the 15520 part number switch for the back up lights. There's where my confusion came from, I couldn't figure out which piece caused the lack of starting

 

On a manual transmission (gearbox) the reverse light switch has nothing to do with the starting relay's trigger circuit.

The red/blue wire going to the 'S' terminal of the starter relay *should* be going to the clutch safety switch if the truck was equipped with one.

The Zf-5 uses a different plug that NP or BW gearboxes, even if the basic part number is the same.
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