Intermittent Starting issue?

I would replace the positive battery cable and check the ground form the battery to the engine block. Also, when the key is in the crank position check for 12 volts at the trigger wire, this guide can help:

https://www.2carpros.com/articles/starter-not-working-repair

Please go over this guide and get back to us.

Thank you for your recommendation, as I will try this. First, I have a question. The (red) wire that goes from the positive battery cable lug on the starter to the body of the alternator has been spliced and now shows signs of having overheated, blue like oxidation on it at that point; is it possible that this could be the culprit? Thanks again for your quick response.

Can you upload an image of what you are talking about?

I have already cut out the bad portion of this wire and replaced it and threw away the bad before being able to take a picture. I believe this is called the exciter wire, but the same failure is still happening. I have inspected battery cables and connectors, and all are good. I did notice that when checking the voltage of the "S" trigger wire in the start position there is only 5.4 volts, and I replaced the neutral safety switch. I am still only getting a click when trying to key start, but successful start when jump the solenoid. I am trying to research now where the voltage drop is occurring.

I found the wire I cut and replaced. Images below, one of top-side of wire and the other the bottom side.

I would test through the ignition switch to see where you are losing the voltage. You should have 12 volts at the purple wire when in the crank position.

I didn't get a chance to work on it today. Will let you know my findings when I do. Thank you. Steve

Messing with the wires at the starter trying to get them further away from header, and now truck will not start even with jumping the solenoid via remote start switch. The red wire that goes on the post with the positive battery cable I assume is the exciter wire and has an elongated white component in line close to where it connects on starter post. I assume (again) that this is either a diode or fusible link??? Maybe this component has a short? Do you know if this wire can be purchased anywhere for replacement? I am trying to get around replacing the ignition switch because I really don't want to drop the steering column and not knowing otherwise how to eliminate possible problem places. Steve.

It sounds like you found the problem, yes you can get the fusible link from the autoparts store and then splice it in. You can use this guide to see if the ignition switch is getting power after the fusible link is replaced.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Please go over this guide and get back to us.

I am attaching a picture of the factory wire that connects to the power lug on the solenoid along with the positive battery cable. In reference to the white-ish component in line here, with "14" marked on it; can you tell me if that is a fusible link, or diode, resister or something else? The other end of this wire is attached to a lug on the back side of the alternator. While at it the second picture is the end of the wire that connects to the small (trigger) lug on the solenoid; is there anything special about the end of this wire? I thought I'd put another connector in its place. I'm getting out of my league here. Thank you.

You are doing good, there is nothing special about the electrical connector, you can just replace it.

I ended up cleaning the front and back surfaces of the positive battery cable terminal that bolts to the solenoid. I used a round wire brush in my drill to make shiny again. There was no sign of corrosion but rather a dark look on each side, which I made shiny again. Evidently this was some amount of coating build-up causing the problem. Having now re-attached all connectors at the solenoid, it has not failed in multiple attempts. Thank you.

Glad you could get it fixed, thanks for letting us know. Please use 2CarPros anytime we are here to help.