Bisqueth

i seem to remember from another thread that the temp regulating flaps are operated by cable on v8s, but by a vaccuum servo on the 5000s.
as my 5ktq avant, after recieving a new heater core and blower motor yesterday, has demonstrated the annoying condition of only blowing out of the defrost vents, nomatter the setting or how hot the box is. the fan speeds up and slows down, but it seems the flaps aren't doing what they ought.
this leads me to suspect the vaccuum servo that supplies the lines that move the flaps.
so the question becomes: where is it? is it able to be found without removing the whole heater box thingy again? (i hope so)
thanks, as always

jurq

It is behind the glove box.

Kneale Brownson

Defrost is the default setting the system goes to automatically if there is some problem.

Did you install the box or did someone else?

The servo may not be the problem. The problem may be the Bowden cable adjustment at the heater core box. Bentley shows an adjustment procedure for the flaps control.

There also is a vacuum hose connector to the heater core box behind the center console. I think it's the vacuum motors the hoses supply vacuum to through that connector that actually manipulate the flaps.

The V8/100/200 system does use an electric motor to serve the function of the Bowden cable (tell which flap motor to operate in what manner).

Randolph

If it's blowing out the defrost then whoever installed the core likely didn't connect the vacuum hoses right. Like Kneale said, behind the console are the vacuum connections to the air distribution flap. Your temps flaps are operated by the bowden cable that originates behind the glove box. You may have to remove the console side panels, radio et al to get access to the hoses to make sure they are hooked up properly. Also, the problem could be with the controller but I doubt that if this started right after having a new core installed.

Randolph
87 5KCSTQ
93 928GTS