Stals when a/c control is moved to any vent position

[FiveOfastback]

Stalls when a/c control is moved to any vent position

My 88 stalls whenever a vent position change such as floor or mix or a/c> Are the selector switches prone to problems? HELP!

 

[HISSIN50]

There is an extra load created on the motor when the A/C is turned on. The IAC is responsible for bumping the idle up to accomodate this.

And the system can bog when switching the HVAC fan on to a higher speed. This can be normal - the alternator can take a second to accomodate the increased load.

Good luck.

 

[fiveofanatic]

Big ol' vacuum leak, maybe?

 

[2000xp8]

Big ol' vacuum leak, maybe?

Exactly what i was thinking.

The vacumm is used to keep the valves in different positions. I think naturally it's on floor, that's why it doesn't do it all the time.

 

[QDRHRSE]

Exactly what i was thinking.

The vacumm is used to keep the valves in different positions. I think naturally it's on floor, that's why it doesn't do it all the time.

Me too. The heat & AC controls are vacuum operated.

 

[HISSIN50]

A vac leak should cause a higher or hanging idle, not stalling.

Here is a marvelous drawing of the pathways for the HVAC.
Good luck.