Non-electronic climate control issues 1992 Thunderbird

[Stangzilla]

So I have a 1992 Thunderbird standard model 3.8 liter V6 with the non-electronic Dual climate control. The vehicle has just under 60,000 miles on it runs like a charm lots of new and updated stuff on it. Anyway just recently when I try to turn on my air conditioner or heat by pressing the button it just felt really funny and made a weird vacuum sucking sound.! When I turn on the fan nothing comes on because I believe the unit is stuck in the off position. When I press like I said any other buttons they're kind of hard to push in like there is some sort of pressure being backed up inside the unit.!? Any thoughts..? Thank you in advance..!

 

[Stangzilla]

So I have a 1992 Thunderbird standard model 3.8 liter V6 with the non-electronic Dual climate control. The vehicle has just under 60,000 miles on it runs like a charm lots of new and updated stuff on it. Anyway just recently when I try to turn on my air conditioner or heat by pressing the button it just felt really funny and made a weird vacuum sucking sound.! When I turn on the fan nothing comes on because I believe the unit is stuck in the off position. When I press like I said any other buttons they're kind of hard to push in like there is some sort of pressure being backed up inside the unit.!? Any thoughts..? Thank you in advance..!

So something new has happened the other day every once in awhile I'll mess with the buttons to see if anything changed and in fact it did I was able to operate all of the buttons and my fan came on and the AC works perfectly period after a couple of hours I turn the fan down and all the buttons were working fine. Tried to turn it back on again again all the buttons are working fine but the fan will not come on because the off button is the only one that feels strange it's very hard to push all the other ones feel normal. The compressor is cycling on and off when I use a defrost or air conditioning function but the fan will not turn on because that button is stuck to off I believe. It worked before what causes these buttons to work and then not work. Oh by the way I found a vacuum leak at the firewall that I repaired not sure if that had anything to do with her or not but it's fixed and it still does the same thing