1992 Ford Bronco won't start

It's a Ford Bronco '92 4x4 automatic, been having problems starting it so the selenoid on the side was replaced, then the truck would start most of the time. However from time to time it would just make a clicking noise again and not start, but eventually would if ya let it sit for a while, but 2 weeks ago it started and when it was shut off to run in somewhere then come back out to start it again, it wouldn't. Now it has never started since and I bought a new starter which has the second selenoid attached to it and still nothing. Checked the battery, battery cables, the wirering connecting to the battery from the starter and so on. Still nothing! Please help us we are going out of our minds over this truck and we really need this viehichle to run again. Signed, desperate & baffled