about 2 months ago, while my wife was driving the a/c started blowing out of the defrost vent only, to correct this i pulled the dash down and looked for a vaccum line broke or disconnected. did not find either so i zip tied the vent open so that it would blow out the vents, about three weeks ago while changing her oil, i found the vaccum leak under the hood on a cracked line, so i fixed the leak and went back behind the dash and removed the zip tie. Yesterday it did the same thing! this is the same 97 i have had on here for 4x4 acuator ? COULD this all be linked together somehow?????? please help

 

I believe that there is a service bulletin at the dealer about a new vacuum switch that is located on the transfer case upper drivers side. They have replaced it with new design, the old one would allow trans fluid from the case to get into vacuum lines in the dash making operation of vents and a/c problematic.

I think there is a an article either here or on s10crewcab.com about how to replace.

You might also check your tranny fluid. There is also a possibility that the rear trans seal to transfer case is leaking fluid into the transfer case and allowing the fluid level to rise so that the vacuum of the switch is sucking up fluid.....

 

is there a chance it has been recalled for this problem?

 

No there wouldn't be a recall for this problem because it isn't a safety issue.

I definitely would make sure that you are getting vacuum to the dash controls. Sounds like it went into a default mode for one reason or another.