Heater box Quextion

[Davis]

I got in my truck the other day and tried to switch it to defrost mode. It wouldn't go. The heater box is of course notched to fit the turbo. It has been a long time since I have driven my truck and cant remember if I used to have this problem. Would this notch be blocking a flapper door and causing my problems?

 

[Dave R]

Shouldn't be the cause of the problem, unless yours is radically different than mine. The section notched out is just the path from the blower to the heater core, ther is no blend door in there. Are you sure you don't have a vacuum leak due to some critter making a home somewhere while it was stored?

 

[Davis]

Vacuum leak? I thought that door was actuated by a cable.

 

[Dave R]

Two of the doors are mechanical, one is vacuum.

After re-reading, are you saying that the operating lever won't actually move into the defrost position?

 

[Davis]

yep.

 

[Dave R]

Ah, then that's different. If you were in this area I'd suggest rust, but I don't think that's a problem for you.

Does the lever/cable move freely until that point?

 

[Davis]

yeah. i get over about 2.5 clicks or positions and then it just doesnt want to go any further.