1995 Chevy S-10 Ventilation problems. Only defrost works

LILIALAIN

MEMBER
1995 CHEVROLET S-10
4 CYL
FWD
MANUAL
130,000 MILES

The ventilation settings haven't been working properly for the last few months. At first it would work some days and others not! Now it wont work at all as the air comes out only from the defrost vents no matter what the setting is. My husband is not a mechanic but he is willing to give it a try if some kind person would give me a hint as to what we should try to do first in order to hopefully fix this problem. I have read through Googgle researches that it might be a leak from a vacuum hose. But we are still looking for those vacuum hoses? What do they look like? We have started to dismantled the front dash decorative pannel but haven't seen anything yet. Should we remove the whole dash itself? Please anyone help us. We unfortunately can't afford to have it repaired by a mechanic! Thank you so much in advance for any hints.

1 Reply

JAMES W.

MECHANIC
2,395 POSTS

The default position for the vacuum control system is defrost. That means, if there is no vacuum to the system to change the air settings, it goes to defrost. The vacuum lines for this system are small plastic (1/8" thick) lines of various colors ie; red, blue, green, black etc. The feed line will come from the intake manifold or a junction on the firewall and I believe it will be red. Find this tube and verify vacuum and that are no cracks or splits. This feed line goes directly to the selector switch on the dash. Check for vacuum at the switch and that it is going through it to the various damper controls. Hope this helps.