GMC Repair: gmc safari air, gmc safari, vacuum devices

Question
I have a 97 GMC Safari and t he air blows throught the defrost vents and not through the vents on the dash.  Is this a tube broken? and how do I get to this to fix it.  Thanks.

Answer
This is a very common problem and in most cases it is the fault of the vacuum line that goes from the engine compartment thru the firewall to your under dash vacuum devices for heat and A/C.

This broken or disconnected line is usually a result of previous work being done in the engine compartment or within the dash area.

Look in the areas of where previous work has been performed and you may just find that it was left disconnected during the repair.

If no work has been done, Search the firewall from the engine compartment and look for a small black plastic or rubber tube that goes thru the firewall.

let me know.

autohelp