With the assistance of the good people here on WF I was able to fix my broken blend door actuator arm today!
During this time I was also doing an LED swap on my dash and gauges. Knowing the dash was going to be partly disassembled I figured it was time to fix this HVAC system.
I am posting this to help others who may suffer an HVAC that fails to blow through the correct vents. Mine failed to work on the dash vents but did work on the defrost and floor..
If you suspect the blend door arms are broken you should have already inspected all of your vacuum lines to make sure one of yours hasn't fallen off.
A particular culprit is the one located under the battery tray.
Alot of people solved their blend door issue by reattaching this hose.
If you haven't heard, this job can be extremely daunting due to the awkward positioning the blend door is, in relation to the dash. It is to the right and up from the gas pedal on a 97 TJ.
Upon inspection I found it was one of the two upper blend door actuator arms (yes there are two upper arms and one much lower). The lower arm appears to be a different part number (don't quote me).
I used this part, from this website-
Jeep Parts, Jeep Tops And Jeep Acccessories
Mine had broken off inside the blend door. Half of the arm was still stuck, broken and sunken a bit inside the blend door. To snatch it out, I stuck a long skinny wood screw into this remaining piece and ripped it out with a pair of pliers.
Once removed I installed the new arm and reattached the metal bar onto the hook end of the new arm. On top of that I reattached the locking washer.
I had heard and read about people removing seats and dismantling their dashes pretty extensively to do this repair. I had an easier time by getting completely upside down like so
Lol I know! Still pretty torturous but not as bad as laying on the door sill with your feet on the ground and cracking your back. This saved me what could have been alot of extra work and agony.
I hope this post helps some people out. I dealt with this busted heater/ac for a full year. Using this upside down maneuver I had this job done in about 40 minutes. Well worth it!