BROWNIEBOY525
The old fleet
i have ac only coming out of the defroster im guess it has a vacum leak but im not sure. what do i look for first?
Mine's been acting funny lately too. If I shut the truck down and leave it in "Max AC" position it'll restart and discharge in defrost mode until I cycle it to "Normal AC" and then back to "Max AC". It works fine otherwise, but I don't remember it doing that until this summer. Any ideas?
Ryan
On every vehicle I have had to do that, it has always ended up being the vacuum-switch made onto the A/C-Heater control itself
When these go bad, they default to defrost.
Usually what kills the vacuum-switch is excessive heat over long periods of time from a too-small fan switch; the fan/blower switch gets hot and melts the plastic vacuum-switch; after a while, the constantly heated/melted plastic becomes brittle and develops a crack, thus losing vacuum.