Here's a good one to rack your brains.
For the past 6 months, my blower motor has been randomly looking power. Doesn't matter what setting the blower or temp controls are. Happens with heat and AC.
I had NO idea where to even start with the exception of testing the fan and switch. Before i had a chance to do that, i noticed a common denominator.
Seems it looses power with the steering wheel tilt all the way up. Once i drop the wheel, it would kick back on. I always raise the wheel upon exiting and drop it to drive. I put anywhere between 40 and 60k a year and im in and out of the truck a minimum of 10 times a day. This leads to a ton of movement, probably more then the factory tests for
My thinking is that a wire on the ignition switch might be coming loose, but i would figure i would loose power to a number of other things on the same accessory circuit which im not seeing.
What else could provide power to the blower motor, and only the blower motor in the steering column area?

 

The wriring in these truck sucks. Like it was made of solid plastic, so anywhere there is repetitive movement, the wires just eventually break.

I took my colum apart and found three in there that were almost broke apart.

I also had to repair most of the wires that connect the doors to the body, inside that boot they were almost all broken. Windows and door locks all started to quit working.

However, I have just taken my fan out, and it needs a push to get it to start spinning. So I dont think my problem is the same as yours.

Im ordering a new fan today

good luck with your wiring

 

Sounds crazy but take out your ignition switch....if theres two burnt terminals Thats your problem.