Will due over the weekend.. Thanks

I have yet to get under the truck to test the purple wire at the starter solenoid as Tech 2 suggested.....

But I do know now that I have a neg signal at the fuse relay pin85 along with the pin30 Hot, power at pin86 with key at start and pin87 to the starter solenoid (which I assume is the purple wire).
This Ground pin85 to the ecu may be intermittent tho. I was a no crank this morning and after pulling the relay for a few signal tests, Once all 4 pins on the relay passed, I re-inserted the relay and it then cranked and started.

Possibly SOLVED !!!! I need to give it a good cold week to be sure but here is what I found last night....

Loose starter relay in the fuse junction box. Yup, possibly that simple. I have seen video repairs in the fuse box under the hood because of slight corrosion. For the most part, my junction box looks 10x cleaner then the ones on the repair video so I didn't suspect. I was confused when double checking each of the 4 posts/tabs on the starter relay and that they were all sending proper signals. I finally had a helper and had him turning the key to start while I checked purple wire and a few other things. I finally rested a finger on the starter relay during the Key in start to feel the click of the relay and with a bit of angled pressure on that relay, the starter kicked in and started the engine. Not sure as to why or how it became loose enough to lose a connection, especially when cold but I gave each tab a slight bend to give it a snug fit and so far so good. Waiting for some cold nights to be 100% sure.
Thanks for all the help for those that replied! Happy Holidays!!!

Ron

Keeping our fingers crossed.

"Sometimes the little things are big" - Yogi Berra

Same issue with 2007 burb
 

Hello @94burb just curious if you still feel that bending the relay post did sole the issue? I’m having the same sporadic issue with by 2007 not starting at times!