720 starter woes

[Roughnecks]

With in the past 3 days I bought a Datsun 720 which has had some starting issues.
As it sits now the starter will not crank at all, however you can hear the click of power going to the solenoid, with the electric fuel pump which is ran through a toggle switch.
Now when I bough the truck I was aware that the starter had been replaced. At least twice. The first time it was replaced with an automatic starter, this was removed and replaced by the previous owner with a manual starter from napa (not sure of the name or type yet as I have not looked); however when the previous owner replaced the starter, some of the bolts where stripped which he corrected with washers. This however made the starter grind and clunk like nothing I've ever heard before, before firing up after the second or third crank and a little gas. It started up at least a dozen times in the last two days and drove well over 70 miles in the last few days. However today at lunch whe. Then I went to fire it up during lunch, letting it crank twice without success before backing off the starter and trying agin. On my second attempt the starter did not engage making only 1 tick noise as I turn the key to the starter. It's my belief that the tick is coming from the solenoid, and that the starter is either stuck or broken somewhere inside.
However I'm not sure as to what the problem really is in the starter its self, the way it was installed or the god awful work on some of the wiring. I'm hoping that I will not need to replace the starter but I am unsure at this point and would welcome any advice, or answers you can provide. Thank you for your time.

[Roughnecks]

So figured out was up; positive wire came unhooked from the starter. Turns out there might be a secondary power sorce in these trucks. I figure this because I unhooked my battery and then tested to see if the lights work, which they did. Any way hope this might help others.

[PEZi]

Sorry we didn't get back to you sooner, man! To me it sounded like something in the wiring or even a dead battery... but I'm glad you figured it out!