97 B4000 Help

[fordever]

Ok I did use the search to no end, and I usually not the type to ask for help but I am stuck without a clue. So this is my problem went to turn on the defrost to day and the ac comes on it comes on all settings. It was working fine last week and I just can't figer out what the hell is wrong lol. So any input would be much appreciated. And before I forget it a 97 4.0 B4000 se.

 

[RonD]

The AC should always come on when Defrost is selected, it is used to dry the air blowing on the windshield, this clears the fog much faster.
If it wasn't coming on before then something wasn't working right....before.

If it comes on in other positions, Defrost off, then selector may be at fault.

 

[cvar]

Yes, A/C is supposed to come ON in all settings except two: OFF and VENT. While defrosting, the idea is to use A/C to dehumidify the air, not really to chill it. That clears your windows faster, even in winter.

It's the same principle as using a dehumidifier in a damp basement. A dehumidifier is really just a portable A/C unit.

 

[ndccpf1]

I used a yellow highlighter to remind me. The ONLY two positions where the A/C is NOT on is the symbol to the left of air-flow to the face and the symbol to the right of air-flow to the feet.

A/C will come on for all other positions, including the symbol to the right of airflow to FACE and FEET.

 

[fordever]

Thanks all ! I did get it to work, it was a hose that went to a little vacuum block thingy beside the glove box. I had like two little hoses off of it, so I hooked them up and bam it worked

 

[RonD]

Thanks for the update and fix