Learnin' Time

PurdyPony · **Joined:** Wed Jan 25, 2012 5:46 pm **Posts:** 57

Did I mention that I've also got a wire hooked up wrong?

With the key in the on position, the starter engages.... :yikes:

I'll need to remedy the starter thing before I can check voltage....

DRRummel · **Posted:** Wed May 20, 2015 2:07 pm

Sounds like you reversed the two wires from the ignition switch. Just guessing, I think the ‘start’ wire going to the coil instead of the solenoid. So the 'run' wire would be going to the S terminal of the solenoid.

As I understand it, this I how the stock setup should be working:
Starting:
When the key is in the "start" position the only wire that has power from the ignition switch is the wire to the small "S" terminal on the starter solenoid. When power is applied to the "S" terminal from the ignition switch, the starter solenoid closes. When closed the large terminal to the starter and the "I" terminal to the coil gets power. The 12v power from the I terminal drives the coil for starting. There is no other power going to the coil.

Running:
When the ignition switch is released to the "Run" position there is no longer power to the "S" terminal. The "I" terminals and starter power terminal on the solenoid is now open. There is no voltage going the coil from the solenoid and the starter is no longer cranking. There is power going to the coil, but it is now through the ignition switch though the wire that contains the resistor wire.

Another way of wording it:
The coil wire has a splice in it. From the coil, one end goes to the "I" terminal and one end comes from the ignition switch with the resistor wire. When in the "Start" position power can only go to the coil from "I" because the ignition switch side with the resistor wire is open and the solenoid is closed. When the ignition switch is in the "Run" position, power can only go to the coil from the now closed ignition switch because the solenoid and the "I" terminal is now open.

About the coil voltages:
When cranking the motor, the solenoid passes 12V from the I terminal to the coil. Once the key returns to the Run position, the solenoid opens, I terminal no longer has 12 volts to the coil, but the ignition switch now provides 6.5-8 volts to the coil via the resister wire. If you were to run 12v to the coil constantly, you would shorten the life of your coil.

Of course, with the aftermarket distributor, this might all be off.

PurdyPony · **Joined:** Wed Jan 25, 2012 5:46 pm **Posts:** 57

It is alive! Sorta.
She idles, but won't throttle up.
Timing seems almost there, but I think I have a carb issue as well.

Also, that knock... :yikes:

https://youtu.be/IBEtdWZ-pGI

DRRummel · **Posted:** Tue Sep 08, 2015 12:29 am

UGH, no idea.
I will ask around.

PurdyPony · **Joined:** Wed Jan 25, 2012 5:46 pm **Posts:** 57

Finally figured out why the engine was running so rough. Turned out the coil wasn't getting a full 12 volts. Ran a test lead from the battery to the coil and she fired right up. Now to get a permanent solution in place and set the timing.

https://youtu.be/If8PO92DjPU

DRRummel · **Posted:** Sat Sep 12, 2015 10:37 am

Great.

PurdyPony · **Joined:** Wed Jan 25, 2012 5:46 pm **Posts:** 57

Sorted out the voltage problem to the coil. Had to remove the remnants of an alarm system that was installed by a previous owner and reconnect the ignition wires to their original spots in the harness. Part of that was to bypass the pink ballast wire to ensure 12 volts to the coil. This was done with a separate wire. During the troubleshooting, found out my 1 wire alternator was putting out a "measley" 40 volts to the battery, so I put the old alternaor back in any everything is working as it should. Bonus points for getting the wiring under the dash cleaned up! :banana:

Now to get the AOD pressure set with the carb and get the timing finished.

DRRummel · **Posted:** Mon Sep 14, 2015 2:07 pm

I am so excited.

PurdyPony · **Joined:** Wed Jan 25, 2012 5:46 pm **Posts:** 57

And the electrical gremlins have raised their ugly heads again. Back to a starting issue, but this time I think it might have something to do with the ignition switch. When I try to start the car, the engine turns over but doesn't catch, like it's not getting spark. However, it will start when I connect a remote start switch to the solenoid. The difference from stock is that I ran a separate wire from the ignition to the coil to bypass the balast wire. I definitely am not an electrical expert. Any thoughts, advice, suggestions, etc would be appreciated.

On a lighter note, I was able to get a few days of driving in before the gremlins showed. I changed the rear diff from 3.25 to 3.80 and man what a difference!!! Gonna need to get those new wheels/tires soon! (after I get this latest issue sorted out). 205/70R14s aren't going to cut the mustard!!!! I'm planning on running 235/60 15s in the rear and 215/65 15s up front on black spoke US Mag wheels.

Steve

PurdyPony · **Joined:** Wed Jan 25, 2012 5:46 pm **Posts:** 57

Follow up to the ignition switch: it was indeed bad. I replaced it with a new Scott Drake switch. Fitment was fine. She fires right up again!!!

Mustang Club of Maryland

Learnin' Time

Who is online