I have not heard of any similar issues, but I believe the fan control signals come from the TIPM, so they should look there.

 

You appear to be the winner. They have had the truck for 4 days. They have determined that the TIPM is probably the culprit. They are replacing it tomorrow. Hopefully this fixes the problem.

 

Has the blower motor been replaced? If not, tap it lightly the next time it doesn't start.
I'd bet your next paycheck it's bad.

 

When it was not working there was no power getting to the the fan motor, which is why they determined it was the TIPM.

 

I'm still looking for wiring diagrams or the service manual for your truck. Do you remember if the no power to the blower motor was traced all the way back to the TIPM? I'm wondering if there was just no voltage at the motor, or truly no voltage leaving the TIPM. If the wiring hasn't been verified, I wouldn't be buying an expensive TIPM.

 

Did they confirm it was the TIPM? I'm having a nearly identical issue on a 2013 Laramie the IS NOT covered by warranty. I'd rather not have to shell out that kind of cash for a repair if I can help it. Already had to pay out of pocket for the Transmission Shift Solenoid Pack replacement...3 days after my warranty expired. Will NEVER got back to that dealership again.

 

What exactly are your symptoms? I just solved a delayed time to start of all my HVAC controls due to a bad 8.4 radio. Controls were delayed until the 8.4 screen would come on which would be anywhere from 1 minute to 4 minutes, at which time screen came on and push buttons below the screen would then work. PM me if this describes your problem.