1991 GMC Sierra C1500 - Ventilation air flow problems

HOOTY21

MEMBER
1991 GMC C1500

I have a 1991 GMC Sierra C1500 that I recently purchased.

When using the ventilation system, and set such that the air should come through the driver/passenger vents no air flow is present. The fan is operating at all three speeds and I can hear air flow, but it is not coming through the vents.

Question: Where is the air going, and what can I do to make it come through the vents. Is there any duct work that may have become disconnected, a damper that is malfunctioning?

Winter is coming, would be nice to have heat where I need it.

1 Reply

CMAK9

MEMBER
2 POSTS

In the middle of the dash, kind of behind the ashtray, there will be a connecting rod that falls out of it's small circular hole. This is kind of hard to describe, but you will probably need to remove a few modules from that area, such as AC control, etc. You will also kind of have to "stand on your head" to get to the problem. If you will take a few things apart and look above the transmission hump area, you will see the part I'm talking about.

Leave the AC control connected and you will be able to turn the vent control between defrost and vent, which will help you see the part I'm talking about. If you have difficulty making the part go back in, turn the vent setting from whatever it is on, to another setting (such as from "defrost" to "vent" or vice versa). Kind of hard to describe all of this. Good luck with it. It's not terribly hard to do, but you have to disassemble some things.