A/C-Heat control on dash

It could be the linkage to the control or vacuum line to the control depending on which you have.

enblethen wrote:
It could be the linkage to the control or vacuum line to the control

depending on which you have

.

Get ready to hang on to your pocketbook too if you have the new style!

The NEW heater/ac controls are not like in the old days. They are operated by an assembly part that sits at the very bottom of your dash. Mine wouldn't switch from ac to heat every time.......found out what it all entailed to take dash out and the cost to repair at dealership.....I just left it on AC since I was moving to Florida! :W

Ford? You have a vacuum driven system. Look for a vacuum leak....

Many Fords seem to have Vacuum Control for Modes (Defrost, Heat, Mix, etc.). A control valve, vacuum servos, and a supply tank with lines. And Electronic control with a variable resistor and motor/gear servo.
But mice seem to like to chew on both wiring insulation AND vacuum tubing. Apparently both are made with a grain derivative.
Also, any recent work under or near the dash or engine compartment? I broke a vacuum line in a Ford changing the battery.

Thanks all who have responded. Will check out your recommendations.