Two more whimsical questions. I'm sure my name's by now

[Jeffgmcgrr]

First question, my heater doesn't seem to be actuating from mid, floor , defrost. It's stuck on mid... anybody have any tips and tricks for accomplishing this one?

Next..... I have a short, my left brake light will come in and out. I've also noticed that if it's out, and I engage my right signal it'll turn on. I have checked all bulbs and I also part swapped the circuit board if you will, for the light receptacles..

I'm wondering if this is something in the column or if there is a notorious short in the wiring and where that wiring would be

 

[DerekTheGreat]

I can't help ya with the light issue but the heater thing is most likely the actuator servo motor thing. Not sure what year your truck is but on the '88-94's at least there's a servo which is located to the right and above of the gas pedal. This is what switches the vent position. My '89 was toasted when I got it, stuck on I forget but that fixed it. Plus I gave the shaft it rotates a good couple snorts of ATF + Acetone. No issues since.

 

[Jeffgmcgrr]

Thanks

 

[c1500deathtrap]

see if you have some wonky trailer wiring setup.

 

[ima93chevyguy]

Check the grounds at the rear also when you check for trailer wiring.

 

[Jeffgmcgrr]

I do have a tow package on the receiver. That brake light goes out on both the truck and trailer when it goes out. However as soon as I press right turn signal it kicks back on