Ignition Problem

automart

Member
Jan 26, 2006
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Nashville, TN
I'm still restoring a 1970 Mach I, 351C 4v, 4spd, anyway, I have the wiring installed but the key will not engage the starter, I can jump it from the new solenoid and it will start and stay running, if I swap the wires, when I turn the key to the "On" position, it engages the starter (not going to the start position with the key, Just turning it On, which is not right)
 
If you have a test light or meter, test for current at the the 2 small wires when you turn the ignition to START, this wire goes on the small terminal toward the front of car and when hot CONNECTS the 2 large terminals together for your starter. If you dont have a hot comming out when you tern the ignition to start then you have to trace it back. If you do have a hot and its connected to the right terminal then someone gave you the wrong solenoid as there are a few that look alike but not the same inside.
Try this if you have hot from the ignition to the solenoid, pull the other small wire off the terminal and test it for a ground, if it has a ground then its the wrong solenoid. Mustang solenoids are grounded to the mounting strap and you must have a good ground to the wall. test that too. good luck.
 
automart said:
I'm still restoring a 1970 Mach I, 351C 4v, 4spd, anyway, I have the wiring installed but the key will not engage the starter, I can jump it from the new solenoid and it will start and stay running, if I swap the wires, when I turn the key to the "On" position, it engages the starter (not going to the start position with the key, Just turning it On, which is not right)

Your missing the jumper connection for the starter.
It is the other 2 wires from the firewall connector that has your reverse lights.

you need to place a jumper wire across this connection point to complete the starter engage circut.

PB
 
I've spent a month sorting mine out, so good luck. I think you have a problem with the two small wires that push onto the selonoid. The red with blue should be on the post labeled "s" (for starter) and the red with green should be on the one labeled "i" (for ignition/on). If your starter engages, you must have the red/green where the red/blue is supposed to be. If you have a meter, check and make sure your red/green has about 12v when the key is on, have someone hold the key in the starter position and you should have 12v on the red/blue wire (and 12v on the red/green). If you have these two wires pulled off the selonoid, it won't engage the starter, so you can play with this without running your battery down from cranking starter. GOOD LUCK!
 
I tried replacing the selonoid with another but still the same. The light suggestion make sense as I have not finished wiring everything up.
I've tried the two small wires, switching them. The one stays hot when the key is on, the other is nothing.
I'll be back
 
Yep. It's pretty tough to diagnose these kinds of problems without a light or meter. I prefer a meter to know what voltage I'm getting. They are pretty easy to use. If you don't have one, get one that also can read ohms. I always hear ignition switches being a problem and have never found that to be true. I'm betting you have a pretty simple problem and the meter will help you figure it out.
 
Pa Bear89

Could you give me a little more details. I have not wired up the console inside. I do not know about a back up light wire. Is the connection inside the interior or outside on the firewall?

Thanks,

Ronnie
 
that sounds like a wire from the start pos of the switch to the solenoid. use a jumper, and see if it starts. Jumper, as in behind the switch, to the solenoid. you don't need to go thru the firewall yet, because this might not be it.
But when you switched the wires, that was the switched 12v wire and the start wire. which means your switch is getting 12v. So its from there that the problem lies.
Let me get this right though. when you turn the key on, and go in front and jumper the solenoid it starts and runs. Just when you use the key it won't crank? Wire from the start pos of switch to solenoid.
AND you checked ALL your grounds FIRST.
 
HH Head, thanks, a lot you say makes sense, I have something to work with. I have not devoted a lot of time to the wiring on the inside and back. Yes, it will start when the key is in the ON position and I jump it from the selonoid, it will not engage when I go to the start position of the key switch. There probably are a couple of grounds which I have not bolted down yet.

Thanks,

Ronnie
 
automart said:
Pa Bear89

Could you give me a little more details. I have not wired up the console inside. I do not know about a back up light wire. Is the connection inside the interior or outside on the firewall?

Thanks,

Ronnie

It is a four wire connector that comes out of the firewall area just below the shocktower brace to the left of the master cyl as you look at the car.

2 wires are for the rev lights, one side will have 12v with the key on and the other goes to your rev lamps.
the other 2 are for the starter to engage, one goes to the s or second term on the sol. the other will have 12v when the key is in the "Start" position only.

thats what make your starter engage from the key.

PB

Ps, If this is an org 4sp, it (the jumper connector) was on the wiring harness that went to your shifter for the rev light switch.
If it was an Automatic, it is wireed to the net saftey switch.
 
OK! Now we are getting somewhere, I do have a 4 prong (2 female and 2 males) that are empty, I wonder where the wiring is that attaches there? To make a LONG story short, I paid a person to restore this car, after 2 years, it was given back to me in boxes and bags. It took a trailer and 3 trucks to load it all back up. I had a body man repair all the previous screw ups and now I'm trying to fit the puzzle back together. Did I mention....I hate puzzles! ha!

Thanks,

I'll try to connect the plugs somehow tomorrow.