So I almost made it to 250k miles without a single problem with the stock air and heat system. Anyway, we went on a drive today and about half way through the day, the vent system stopped working. The blower motor was still blowing hard but it wasn't really coming out of any vents that hard. I was using the regular A/C at the time.

I messed with the mode knob a bit. The floor vents work good but the dash and defrost vents barely have any air flow when on those settings.

Am I looking at a mode door problem here? How hard is it to get at? The HVAC system is one area I haven't ever worked with before.

Thanks as always!!

Vacuum connector is near the throttle pedal and you should be able to do some back testing. Might be debris jamming the doors. Possibly a bad vacuum line most of the vacuum stuff is near the throttle pedal the other is the fresh air door against the passenger kick panel.

Ok thanks. I will check into that. I should've added, the recirculate vent works as it should. Opens and closes fine. Maybe another vacuum line is bad? I haven't heard a vacuum leak anywhere but at least it's a good place to start looking.

I think I got lucky. I took some time and went through the vacuum system. Replaced some brittle tubinh and connectors. Everything works as it should again!!

Well I guess I wasn't so lucky. My vent issues came back!! Is there such a thing as a color coded vacuum diagram?

Would this type of issue be caused by the mode switch itself?

Might find one in the FSM. IIRC.