Thought I'd drop a line on where I found my defrost actuator.
I took the glove box out and it's on the air box just right of the glove box.
The actuator was stuck on defrost mode because it had a broke final drive gear.
I took the gear out of the dead actuator that I had just taken out of the Pete 357s blend door a couple days ago and it worked perfectly. I did have to press shafts in and out to make the swap.
The T800 defrost door has not worked right for several years but I could get it to switch from defrost to vent by cutting the truck off but most of the time by turning the fan and AC/Heat off for a minute and then back on.
Last week though it got to where it would not switch back.
I warm my lunch up on defrost every day so I need defrost and vents working.
Now the air is blowing 3 times harder with all 4 vents open.
I had been keeping the right two vents closed so my air would at least blow like it was on low.
This truck actually has a heater valve which I like under the hood that also is operated by an electronic actuator that feathers how much hot water if any goes into the heater kore.
It also has a freeze switch to cut the AC compressor off just before the evaporator freezes and its located just inside the blower box under the hood above the evaporator on the firewall.
It has a temp sensor stuck down into the evaporator coils. For air to blow as cold as this does this switch is a must have. At 26 PSI on the low side, saturated temp of the evaporator should be 30 degrees. It likely seldom gets that low as it battles all the heat but if it does and the evap even thinks about freezing the freeze switch will cut the compressor a few minutes.