97 T4R - manual enviro cold/heat linkage moving to cold; not moving to heat

[4R-User]

97 T4R with manual environmental controls (levers with wire linkages).

The linkage is to move a flap below the glove box that opens/closes the supply of heat but the linkage does not close the flap (moving the lever to heat); if the flap is manually closed (heat position then does provide heat) moving to the cold opens the flap (wire retracts linkage to the flap and the flap is opened).

The cold/heat linkage won't go all the way to the left (approximately stops at 1/4 up from the cold position) and does go all the way to the right (heat).

If I assist the flap while moving the lever, I can feel the linkage's pressure but it isn't enough to move the flap; it seems that the linkage rather deform (it shifts position) when moving the lever to the right (heat).

Any ideas?

 

[brillo_76]

My 1998 does the same thing. Except that if I assist it, it works perfectly fine. If I don't, it will not go hot. I thought about taking the cable off the bottom and blowing graphite into the tube to lubricate it as it would help reduce friction.

Sent from my SM-A536V using Tapatalk

 

[Romeo1]

I cheated. I swapped in a new control stack with cables and everything. You could maybe try lubing the cables with some old school speedo lubricant.

Cables are funny. It all depends on the construction. Some you can resurrect, some it's just a fool's errand.

 

[4R-User]

well this was weird

i was checking the linkage (moving the cold/heat lever environmental control) and moving the flapper valve back and forth (in no particular order)

something made a 'clunk' sound

and now the linkage properly moves the flapper valve open and closed


there must be some intermediate connection between the cold/heat lever and the flapper valve that now is articulating properly