Good day folks!

I believe I am having an electrical problem with my starter on my 4.6 V8.

When I turn the key to start it I hear a muffled clunk coming from the firewall relay and nothing else happens (it did start twice since but not anymore). I know it's not the battery cause the headlights stay on when I try to crank it and I tried boosting it too...

So far I tried
1)tapping on the starter.
2-shorting the solenoid but I just hear a click (with ignition on).
3-checked fuse 21 which was good.
4) I crawled under the truck and removed the 2 wires connecting to the starter solenoid (the one on the starter itself) and the 2 ground wires that go on the bolt holding the starter (top bolt which was a real pain to get at..

So my question here is even with those wires disconnected, when i turn the ignition on(just for the sake of diagnosing) I still hear the same exact click from the firewall area. Which tells me there was a short somewhere before power gets to the starter maybe?

It was no fun working outdoors in -20C for 2 hours and it got dark so I didn't have time to hook the starter wires back on and try but I will do that tomorrow and let you know ...
just wondering if anyone else had the same issue and what did you do?
Thanks
Adam