Fan diverter switch problems

[KHitman]

For some reason, my fan diverter switch decided to stop working today. Its the switch that changes the fan from floor to defrost to a/c, etc. It is stuck on the defrost setting. I can shut the whole thing off so it seems like the switch works.

There is a 4 prong electrical connection on the back along with what looks like 5 colored vacuum hoses underneath, even though the plug looks like it holds 6 vacuum hoses. I couldn't find a hose laying around in the bay anywhere.

Anyone had this happen that could steer me in the right direction to get it fixed? The wife would not be happy riding to Vegas with no A/C...

 

[luc]

The unused ****** on the plug is the vent for the system.

Your problem is with the mode door or more exactly with the 2 positions vaccum motor that control it.
1 position sent all the air to the AC vents and the other one to all the vents EXCEPT the AC vents.

The vaccum line for it is the yellow one and when you select AC (the snow flake) vaccum go to the vaccum motor (the only position that you have vaccum going to this motor).

Luc 00GTS

 

[Tom F&L GoR]

It might also be the vacuum source to both vent door actuators. Since you said defrost only (and that it does not come out the heater ducts) it sounds like maybe neither door is working.

There should be a very small diameter plastic tube on the passenger side near the firewall leading to the intake manifold somewhere. You said you couldn't find a hose laying unused - did you find the one that is used?

 

[GT40DOC]

I agree with Tom, look for a main vacuum hose problem.

 

[KHitman]

Thanks for tips! I started checking where all the lines went. It appears I might have had a main vacuum issue. I "fiddled" with that main vac line going inside the firewall from the intake plus manually activated the 2 vacuum motors on the passenger side of the car plus the one main vacuum motor under the hood by the air intake.

It appears to be working fine now so something I messed with fixed the problem.

Thanks again for pointing me in the right direction!!!