waterboy 72

My door that controls my heat and ac mix is not working at all any more it is stuck on ac at the present moment. Has anyone had this problem and if so how do I fix it? That is without giving my garage a $1000 to do the job?

waterboy 72

Oh btw I have a 99 f-150 super cab step side 4.6L 4x4 it has been an awesome truck so far.

Austin97

First things first check fuse 113 under the hood, it's a 40 amp and number 5, 15 amp, under the driver's side dash. As for the blend door actuator, it's a PITA to replace. First you have to unhook the negative battery cable and let it sit for like 15 minutes because you have to unplug the Airbag Module and you don't want power going to it when you plug it back in. It's behind that black panel above the hump in the floor below the center of the dash. You have to pop that panel off and pull the carpet back and there's a like 2.5" by 2.5" by maybe 1/2" thick square behind it on the passenger side mounted to the air box. You have to pull the floor vents that go to the rear back if they're there, I guess a regular cab probably doesn't have them, unplug and I think remove the Airbag Module. Anyway once you get everything out of the way so you can really get at the blend door actuator the bolts go up so they're hard to find and get a ratchet on. That's if the actuator itself is bad. It's always possible that it's the selector that is bad, or wiring between the two.

waterboy 72

Thanks a ton looks like a weekend project. And sounds like a major pita lol. I'll get back to you and let you know how it goes.

Austin97

One of the worst parts is the damn plastic floor vents. The shop manual tells you to cut the bottom half so it's easier to fold back, but i couldn't really find anything that could get in there to cut it. I had someone helping me so they held it back while I swapped the actuator out, which sucked. I think I would cut the plastic from the outside and cut it right out and then just put it back and duct tape it if I have to do it again.

waterboy 72

Two months later and I got her done it turned out to be the blend door that was bad. So it was a good thing my heater core puked too other wise I don't think I would have found it.