2012 t800 blower fan not working

Check the accessory relay located in the fuse box.
If not that, look for a bad ground connection. Something probably got loose. . .

Did it all go out when you hit a bump?

 

Water ?

 

I'm pretty sure those 3 particular items share a circuit- that's why I would check relays and ground. Water can certainly cause trouble, but I'm betting on a relay or faulty ground. I believe your climate controls point us further in this direction.

Depending on the motor, wiring harnesses would enter the equations with the work you had done, but with what you're describing, I'd be looking at the fuse box for bad connections, checking relays, and looking for a faulty ground.

I'll be curious to find out what you find;
Keep us posted.

Kind regards,
5UG

 

Some of those KW's are a little different. Not wrong just different and hard to wrap your head around at first. They did not run power through all the switches. The switches when flipped grounded the wire to the panel. That engaged the relay next to the fuse in the panel and sends power to lights and such.
Blower switch works on the ground side. Grounds the motor through different resistors for different speeds.
I was waiting on a T800 guru to answer.
Thanking like the others that a ground wire was knocked doing the transmission or something. When cutting down a forest do not get blocked by the size of the job. Cut down the first tree. Check each of the failed systems one at a time.
I doubt it is your problem but there are multiple connectors behind the fuse panel. I thank all power going out has to go through them. Believe you can see some of them with the left and center dash panel rolled back. That is what they look like when the panel is off the front of the fire wall.
Start at the beginning and use the KISS principle. Keep it simple Sam.

 

Fuses are good but do they have power to them?

 

Will this truck start?