1986 mustang lx 5.0 swap won’t stArt

drew536390

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May 23, 2021
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Hi guys new guy here! Going to try to give as much information I can about my issues. Anything information or guidance would be awesome! I have a 1986 lx (2.3 non turbo) mustang that has a 5.0 302 carbed swapped into it. When I got the car it needed rewired. Long story short I got a American auto wire 15 Curcit kit from CJ pony. I got my ignition wiring ran and I tried to start my car. It will roll over but will not fire. I am trying to use the stock Ford ignition switch, as I don’t want to use the supply gm switch that came with the wiring kit. So I wired the stock ignition up using pins #3 clutch safety switch( just ran a straight wire to starting solenoid. #4 for ignition and #8 supply 12v to ignition. I will add a picture to show better example of what I did. The pins I’m using will be circled green. For the ignition I connected to the small red wire on my msd 6al box. I checked voltage on #4 I have +12v when in run but when I go to start I lose the 12v. I’m not sure if this is the reason, I would assume I need to have that 12v signal. But I’m not sure how to go about this. If anyone can point me in the right direction that would be awesome! Ohh the car did start and run using the old harness ( it was all chopped up that’s why I’m rewiring)
 

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90sickfox

Wasn't a pretty sight...and I've got big hands
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Sounds like you need to find the wire off the ignition switch that's off when ign off but 12v when cranking or running. To clarfy...you think the computer isn't getting 12v while cranking and running, correct ?
 

drew536390

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May 23, 2021
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Sounds like you need to find the wire off the ignition switch that's off when ign off but 12v when cranking or running. To clarfy...you think the computer isn't getting 12v while cranking and running, correct ?
Hi thanks for the reply. That is correct. I checked all the voltages on my stock ignition switch. The pin I have my ignition wire in has 12v when in run but 0v when cranking. From looking around I guess I would need 12v when in run and when cranking? Which is got me confused cause I checked all the pins in the ignition switch and none of them have 12v while just in run and cranking it’s either or I have 0v all the time.I’d also say I need that 12v to drop when the key is off to shut the motor down? I wasn’t sure if I was missing somthing on how the ignition switch is wired up. I have not tried it yet but I’m sure if I left the key in run spot and jumped the starting solenoid it would fire up, correct me if I’m wrong. I guess I need to poke around some more and see if I can find that 12v supply. I was curious if someone else had tried wiring it up like this or done Somthing similar.
 

drew536390

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May 23, 2021
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Do you still have 262 jumpered to 16?
Hi i do not have that wired in. I was wondering if that would be part of my problem also. I was trying to see what that brown/pink wired was actually for. Also looks like I might need the other yellow wire from 37 to the switch to.
 

90sickfox

Wasn't a pretty sight...and I've got big hands
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There is a hot in run and start from the ignition switch. Not sure which one off hand. Technically, if you jumped the relay with the key in the forward position ( not cranking ) it should start if the rest of the wiring is ok.
 

drew536390

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May 23, 2021
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There is a hot in run and start from the ignition switch. Not sure which one off hand. Technically, if you jumped the relay with the key in the forward position ( not cranking ) it should start if the rest of the wiring is ok.
That sounds correct, I am planning on going out tomorrow 8-2-21 try this and see if I can get it to fire up while the key is in run. If that does work then my only issue would be is not having the +12v while cranking. Which then I would need to figure out what I’m missing
 
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drew536390

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May 23, 2021
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Hi guys thanks for all the help, I ened up did get the car running. Found my wire from my coil to the distrubuter was bad. And for the wiring, What I’ll end up doing is just going to use a toggle switch for my +12v to my ignition on my msd box. I’ll still use the key to roll the car over and it should fire up that way.