A/C vents will not work

[Jesse]

1990 model Supra, when i press the vent selectors on my a/c control the light at the top of the button comes on and the vent operates but will not continue to operate w/out holding it in. I have had the car since Feb. and this has been a constant, i do not know the detailed history of this problem though, just that the car has had a "full a/c ovehaul/conversion". it also needs a charge but before i pay someone to do this i figured i'd appeal to y'alls knowledge, thanx.
I did replace the a/c control unit with another w/out any effect hoping that it was an easy fix with the buttons, i have never dug into a dash and air conditioning systems before.
and i am actively SEARCHING for answers btw.

thanks again

 

[CPT Furious]

If the buttons themselves won't stay in, it may be the plastic pieces that hold the button in have worn down. I had the same problem with the standard "vent to face" button and the bi-level button. I got another one from a member and that has worked out good.

You can take the unit apart and see where it is not holding the button in. Mine old one would only have enough leverage to hold the button in when it was removed from the rest of the unit. With it assembled, it wouldn't work.

I can get pics later to help explain...

The cheap-o cletus mod is to wedge a penny or dime in the button to hold it down.

 

[Jesse]

i suspected this but did try a different one from a member here with the same results, he stated that it worked fine as far as he knew so that leads me to believe that is not the problem

pics would be appreciated though since i have an extra one to take apart i might as well try it.

 

[CPT Furious]

I love extra parts...it allows experimentation without fear of totally screwing up the current setup. I'll get some pics up tomorrow.