How hard is it to disable the actuator? I want to keep it on heat

 

look at the drawing below.. the air from the blower goes thru the air cond coil, then some goes thru the heater and some goes around the heater... then mixed to get the right temp....You would have to get past the actuator and make sure the BLEND DOOR was closed for 100% heat... not just damper motor turned off...

also note that the "fresh air door" pulls in outside air to the blower motor. for "max AC", the door closes and you recycle inside air and it gets cooler and cooler... I had that damper controller arm break and let cool air into the passenger side floor constantly... I pulled the glove box out and pinned the door closed all the time so it also recycles the cab air in the winter.. makes the hot air hotter.

https://www.ford-trucks.com/forums/9...-please-2.html

 

below is something I cut and saved several years ago on a 2003 EXP... this might give you an idea ....... this is copied, not mine.

...I decided to tackle the blend door actuator myself. I started at 10:30 this morning and was buttoned back up and on the road by 12:30. That top back screw is a royal PITA to get to. All in all I think anyone with minor skills could tackle this job as long as they have patience and perseverance to complete. You will get frustrated with trying to get that top back screw out...so I suggest stepping back and taking a deep breath because laying on your back beneath the steering column is really uncomfortable.
Here are the steps I used:
1. Remove center consold
2. Removed trim piece below steering column
3. Removed dash tower support
4. Removed left side floor duct
5. Removed dash control panel and unplugged wire harnesses
6. Removed 3 screws holding actuator in place
7. Unplugged wiring harness from actuator
8. Plugged new actuator in to harness and tested operation
9. Reversed the order for installation

 

That top screw on the actuator is really not that hard to get to. If you're on your knees outside the vehicle, looking in the direction of the top screw, under the steering column, through multiple brackets and wires, with a socket wrench about a foot and a half long w/extensions, there's a straight shot directly to the screw. Good luck!