Similar problems with my Cheyenne. I replaced battery and vroom. Two days later, just a click. Had it towed to Shear Performance in Costa Mesa. They cleaned and tightened 12 different cables for maintenance, Then vroom. Especially check the cables to the starter.
Did the old starter work? I know you said you checked the clutch/neutral switch but it is the first place I would look. Then wiring at the starter. Then a test light at the starter and have someone turn the key. Looks like the purple wire needs to energize when cranking.
I haven't checked to see if there is power at the purple terminal wire, when the key is on. Hat Trick, the old starter worked perfectly. The reason for the changeout, I had mentioned earlier in the thread. I decided to have my trans rebuilt, and in turn needed to get a clutch. I had an 11" flywheel and switched to a 10.5". So I needed to get a starter that had two mounting positions that would engage the smaller flywheel. I checked the neutral safety switch again this morning. I unplugged it and tried, plugged it back in and tried again. Still nothing. Charger is hooked up with 12.8v. I will have my wife turn the key while I check the ignition terminal at the starter.
So I was finally able to go out and mess with the starter last weekend. I haven't done anything this week. I've been down with a minor neck injury. When I was out last weekend. I hadn't had a chance to get the wife out to turn the key, so I put my test light on the terminal of the starter solenoid with the alligator clamp on the Neg. battery terminal, leaned the light against the header, laid my phone across the heater hoses, and started recording. That connection, or the fact that the car sat a few days without me messing with it, must have done something. As soon as I turned the key, it cranked over. What changed? I have no idea. But it's cranked every time since then. The issue I'm having now, that my buddy and dad alike say "should be fine", or "sounds normal to me", is when cranking, the pinion gear of the starter engages the flywheel, and then "bounces" back and forth. At first I thought it was smacking the flywheel and the pinion gear spinning freely. I had my wife crank the car (it ended up starting) but I was able to get a video of the starter engaging. You can see if it uploads properly, the pinion gear jumping back and forth, while still maintaining adequate engagement. My wife also kept the key turned a bit too long. So that can be seen as well. My buddy thinks it's loud because I don't have the clutch and pressure plate installed yet, and the trans isn't in either. He's thinking that the pinion gear engaging is echoing through the flywheel without all the other components to help absorb the sound.
So I was going to post a video. But I can't figure out how. I think I described the situation reasonably well in the previous paragraph. One issue at a time, it's coming back together.
I installed the clutch this morning. It sounds a little bit better, but still not quite where I'd like it to be. I'm going to pull the starter and reinstall the shim between the starter motor and its mounting plate. This should push the starter forward and distance the pinion gear from the flywheel a bit more. Hoping this dials it in.
The past few days I have been working on the speaker panel. I trimmed it down so that it fit in it's space snug. I picked up some more spray adhesive. This time I found a heavier adhesive that what I used for the sail panels on the headliner. (Those have actually pulled away in some areas, creating some bubbles. Very frustrating). I made sure to spray several coats of adhesive on both the carpet and the wood panel. I began with the panel upside down and folded a flap around the back of the panel. Then I flipped it and worked my way down. I ended up with enough carpet to cover both sides of the board. I'm sure this was unnecessary, but my OCD wanted to cover the entire thing as soon as I realized I had enough material to do so. I laid the flaps from all sides onto each other, sliced over them and removed the material I didn't need so that it all laid down flat. I grabbed some scrap steel plate, cut out some small tabs. Those were filed smooth, edges rounded, drilled, and painted. This morning I used those to secure the bottom of the panel to the back panel of the car. I used self tapping screws to secure into the metal rail that joins the upper bed panel with the lower. I will install a couple connectors to the speaker wire, and install the speakers in place. I also repainted my rear kick panels.
Speakers wired up and installed. I didn't put any screws at the top of the panel, through the shelf panel, because the fitment after I put the carpet was put on, was very tight. If I have issues with vibrating loose later, then I'll install some. But at this point, I really like how clean it is without screws at the top. I also don't want to drill more holes.