Nissan Repair: a/c dash vents wont work

Question
why would my main vents on my dash not work on my 97 nissan altima gxe

Answer
Hi Zane -

Your A/C vents are controlled by engine vacuum. There are 2 probable things that could cause this:

1. There is a broken or leaking vacuum hose in the engine compartment. Look for small rubber tubes near the firewall of the engine compartment and follow them to see if they are intact.

2. The A/C doors in the duct is stuck closed. There are directional doors that the vacumm system above drives open or closed, depending on what setting you have at the controls (Foot area, mid area, or defrost area). Sometimes they get stuck and the vacuum is not sufficient enough to open them to allow air into the area it controls.

The latter is a big job to fix as the dash has to be removed to access the ducts behind it.

Hope this helps -
aloha
Calvin