Just to let you know, the wire that attaches to the solenoid terminal on the starter is +12V, not ground. The +12V is switched via the ignition switch. The Ground connection is through the body of the starter being bolted to the engine.

Anyways....you found it was the starter and unless there is some bare wires along the steering column making intermittent contact....it has to be the ignition switch.

As far as replacing it, something I have never done, suggest using the search feature as someone has probably posted pictures and hints from doing this task.

Hopefully all it requires is removing the three lower dash trim panels for access to the ignition switch. Might have to remove the driver's seat for better access.

Will check back in a week.

 

There are 3 terminals. One 12v going to the starter and one coming from the battery. Then there is a smaller stud and that wire I checked with a volt ohm meter and it was grounded. Just making sure I am not missing something.

 

You're good.
Another thing you could do is attach the volt meter across the solenoid terminal and the ground terminal; then move the shift lever and watch the volt meter. Apparently +12V is getting to the solenoid terminal when the gear shift is wiggled thus causing the solenoid to move the plunger and this is hitting the flexplate.

Once you get the covers off of the steering column and see the ignition switch (also called starter switch), might find that is it just some worn-through insulation on some wires and not the switch itself. But I suspect it is the switch.

Waiting to see what you find-out.

 

Well I didn't see any bare wires. I changed ignition switch and it still does it. I am at a loss. I don't know what would be sending the 12 volts to the solenoid when the gear selector is moved.

 

Just to be sure that you changed the ignition switch and not the lock cylinder; is this correct?

How about this:
With the engine off and cold, remove the starter solenoid wire off the starter. Get a long piece of wire that will allow you to have a volt meter either in the cabin with you or on the windshield so you can see. Clip the pos volt meter lead to the solenoid wire and neg volt meter lead to chassis.
Then while watching the volt meter move the gear shift between park and reverse and note when volt meter flashes a voltage.
Wiggle any wires or anything that the gear shift linkage touches when moved between park and reverse.

I too am running out of ideas.

 

Correct it was the ignition switch not the lock cylinder. I can actually have the key on and truck off and when I wiggle the gear shift between P and R it will start the truck. I wiggled wires all around the steering column and found nothing so far. Is there any way the neutral safety switch could cause this?

 

As far as I know, the neutral safety switch opens the circuit that applies 12V to the solenoid except when in Park or Neutral. The 12V comes through the ignition switch.

According to the wiring diagram I found online, there is a purple wire out of the ignition switch to the neutral switch to the starter solenoid.
Figure states that the neutral switch is located on the left side of the transmission. However this switch also switches the reverse lamps on....sooooooo......is it possible that the neutral switch is defective and switching 12V that is supposed to be going ONLY to the reverse lamps to the solenoid....hmmmmm....I think you may be onto something.

YouTube has a couple of videos on the 4L60E neutral/reverse switch; shows where it is, how to get it off. One states that the front driveshaft forward joint has to come off in order to get access to the forward bolt. Another states to leave the electrical connectors mated, remove the rear bolt and then it is possible to get the electrical connectors off without breaking the connector.

Interesting stuff....thought the two functions were in separate switch assemblies.....learn something new already today...and it is very early!

 

Haha yes too early for all of this. At this point I think it would be crazy not to just change it.

 

It was the neutral safety switch. Problem solved. Thank you so much for your help.

 

GOOD to hear. Wow...this is something to put into my memory cells.....probably better if I write down a few notes.....

Always good to read those words: "Problem solved."