Good Starter, Bad Starter

Ah sorry, its a 2000 Auto V6

Thanks for the suggestions, the 40 fuse is in working order (I even tried swapping it with another just in case) and the wires going to and from the box seems fine, I tried the switching of gears, it actually got it to start once a few months ago but it was a one time fluke, and I checked over all the fuses in the box (Just to be sure) and they all seem fine.

I should also note that Ive got a remote starter switch connected to the starter solenoid and the Positive terminal (not normally, just when I need to test it), which in order to "kick" it off the past few times I would turn the starter over with it and then it will work. When I connect it I still just get a solitary "click" but the Starter is good (I just got back from the part store where they tested it 3 times and every time was a success).

Thank again for the assistance. This thing is driving me crazy, if I didn't live in the South I would be tempted to look for a cliff to push this thing over. >_<

I dont know if it would matter but on both 40 amp fuses in there seems have some slight corrosion (green and white copper kind) but I was able to clean some of it off and the link is still there unbroken, so Im assuming they are still fine.

No I dont think I ever checked the switch, im assuming its somewhere near the transmission? The Haynes Manual isn't very clear on its location... Would that stop the starter from starting even though Im bypassing the ignition system? With the switch I am running power directly to the solenoid and Im still getting the single click.

Also I did a scan with my OBD II Reader and I've got no codes coming out.

Ahhh I see, fantastic, thank you, Ill check these things out then. Many thanks, Ill report my findings.

Thanks, Ive got the switch hooked up to the Solenoid, I made sure to check diagrams and Ive got it connected to the soldered portion (I've got it to crank up connected to the same place in the past). I checked the relay and sure enough both the Reverse and Neutral register as Park, the rest register as they should. Would that prevent it from starting? That Switch looks like a beast to get out.

Yeah I checked the voltage of the battery in multiple places and its gets essentially the same amount all the way down to the starter, maybe 0.1 less.

The Relay is not registering as it should, when I put the truck in Reverse and Neutral the relay is registering them as Park (D, 2 and 1 read as they should). So once it stops raining (just my luck) Ill try and Tetris that switch off and test it to see if I need to replace it.

Ill take a look at the amps, I replaced both terminals and they are quite snug on the battery posts (one of the other times I had this issue it corrected the problem for a little while).

Ive taken the Starter (with the Solenoid attached as they are essentially one unit) to the part store it will turn over every time, is there a way to test it separately to show them its defective?

Once again thanks for your help, you are truly a lifesaver.