Auto Air Conditioning & Heater Repair: a/c problems, vacuum line, vacuum source

Question
my 2000 astro van blows cold air from the defrost vents and from the back a/c only.  the front vents worked yesterday but have quit now.  what is the problem and how do i fix it

Answer
In MOST cases whenever the air blows ONLY from the defrosters this means that you have a broken or cracked vacuum line from the vacuum source within the engine compartment that goes thru the firewall and into the A/C-Heater control unit.

Look under the hood near the firewall for any broken vacuum lines near the firewall or on the engine. The vacuum line may be made of RUBBER or a small diameter PLASTIC both colored BLACK.

Look carefully. This usually happens when someone has done some work previously done on the vehicle and damaged the vacuum line.


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