Heater/AC Vents

[brad75]

Help! I am experiencing some troble with the upper vents on my 75 Supreme. I'm think it is probably vaccuum related, but I don't know where to start looking. I would be grateful for any insight.

[ragz442]

What kind of problems are you having? Usually, a lost vacuum will cause the air to blow out of the defrost only [default]. I would do a visual under the hood first and make sure you don't have any split, disconnected vacuum lines and then go from there.

[brad75]

Thanks for the reply. I'm not getting anything out of these upper vents. :confused:

[ragz442]

By "these upper vents" are you talking about the dash vents that blow directly towards you? Is the air coming out the defrost vents? This will be hard to diag over a computer. Again, I'd pick up a SERVICE MANUAL, lots of good info and diag charts. From what I can see the mode doors [controls which vents the air will come out of] are controlled by vacuum and the temp is a cable on a/c cars. There's a vacuum tank under the hood, make sure it's connected properly and holds vacuum. Some other possibilities are, loose connection at control panel or a mode door diaphram on the hvac housing. Good luck.

[brad75]

I finally got a chance to look at it tonight. Thanks for giving a place to start to look. It was nothing more than a vaccuum line off the cannister. Boy do I feel dumb. It has been about 30 years since I have screwed around with this stuff,(on my 74 Supreme),and I am thankful that you have a better memory than I. Thanks again!

[ragz442]

No problem, glad I was a able to help out. More times than not it's something simple.