87 Wagon....blower motor works and blows hot and cold..just lost control to the defrost/front window vent...thinking with the vaacum operated controls i have a cracked vaacum hose in behidn the dash somewhere..any thoughts ideas would be appriciated ...trying to avoid tearing into the whole system if anyone knows of an easier fix..thanks

Do your floor vents work? If not, you can pop the hood and check the white canister thing near the passenger side firewall. I know if that vacuum hose is disconnected or the white canister is cracked, your defog won't work, nor will your floor heaters. It'll just blow air out the vents.

 

You can also carefully remove the right side button panel. There are two phillips screws you have to reveal (by removing the buttons with a flat head screwdriver). Pop off the defog button and the "off" button, and you'll see the screws. Then you can pull out the button panel, but be careful. There are vacuum lines and a steel cable attached to it, so don't pull it out far. Get it out just enough to look on the right side of it and you should see four (I think) vacuum hoses attached to it. Make sure these are connected.

 

Those are the only two easy tests I can think of. Might be worth a check.

Also check the vac supply line to that canister for good connection at manifold and/or cracks.

 

I've had one that split along it's length, and another that came off the manifold.