I have a 1992 volvo 740 wagon and I was wondering if anyone could help me find where the dampeners are that direct the sir through different vents because mine is only coming out of the defrost and the floor vents no matter what setting it is one. I was also wondering if anyone could tell me where I could find the heater core because I believe that is the cause of my no heat problem. I would appreciate any help thanks.

 

The air vents are controlled by vacum. If they aren't working, most likely you have a vacum hose that is off or leaking. There should be a small vacum hose that comes off the intake manifold and runs through the firewall into the passenger side. Trace that hose down and look for leaks or disconnects. It should run into a resevoir in the center console.

Good luck

 

As far as your heat not working and heater core being bad, unless its leaking or not circulating due to a blockage or bypassed it is fine. The climate control valve would be your issue and if there is a vacuum line off or cracked then that may be why it wont switch over to the heat. Happy hunting!

 

Thanks guys I found the vacuum hose under the hood and it was cracked at the sleeve that connects to the engine block so I taped it for now and it switches setting I am going to get a sleeve to repair it now I just need to work on the heat part. Thanks for your help.