With your helper at the key, on a crank attempt do you ‘feel/hear’ the relay ‘click’?
But even if does, it could be the copper contacts inside the relay aren’t making a good contact.
The relay controls the ops feed for the starter mounted solenoid. Being the starter is now new I wouldn’t suspect it, and if you can bridge the relay and it cranks the starter is off the table and would have me suspect of the relay (good chance) or the solenoid control wire is open.

You could ohm test the small solenoid control wire first to see if it has continuity (yellow/light blue) and/or check it with a test light at the starter for power present during a cranking attempt. Sounds like a relay issue though..

 

That's kind of what I am thinking is the little wire going from the solenoid on the fender under the hood is not carrying power down to starter although I probed it after the solenoid on it's way down to the starter about 1 inch from there and wire showed hot. I need to crawl back under the truck and test sat the starter connection to see if for real power is going to starter. I'll try and get to it this weekend as I am helping my son and daughter-n-law move.

Thanks for all the replies.

 

I have a little tip for you.
When checking a wire for full power at it's point of termination, have had more than one where the connection of the wire into the ring terminal was faulty.
The wire has juice and yet there is no power where it gets secured to a terminal because the wire crimp at the terminal is no good. You need to confirm power all the way down a wire and where it gets secured to a solenoid for example.. I can tell you it is nice when you find one of those stinkers.

 

I have finally found out what was happening to my truck and why it wouldn't start with the key. After tracing the wires and all the problem was with the security alarms put on the truck after it was stolen in 2009. Unplugged the wire from that unit cut the wires and bypassed it. Been cranking fine but I don't have any security now but that's okay.
Thanks to all that responded, Sencerely, Larry

 

Security system?
That would have been good to know straight up
Glad you found the cause.

 

One of the best security systems I know of is ,
Put a polite notice of your pet , and a picture , of a large snake on the seat with a request to please don't be alarmed if "Herman comes out" because he wouldn't come out this morning so I could put him back in his cage . Would you want to take a chance of sitting next to Herman?