climate control problem

[TheSparo]

ok, so a couple of weeks ago my selector switch for the a/c / heat stopped working , you know the buttons on the unit that change it to feet, head, feet and head, defroster etc. they dont work anymore, and neither does the recirculation or A/C button. i have an S13 model and i already tried replacing the unit it self and still no help. The cold hot slider and 1-2-3-4 slider still works. its only the buttons (electrical) the lights don't come on either when you push them...

there was no help in search, any ideas? i tried a new relay, that wasn't it...

[Flybert]

It could be the mechanism that actually switches the vents. I know that sometimes mine is really slow to switch them over and makes a creeking noise. You might have to pull the dash and start looking around.

[TheSparo]

but why would the lights be out on the buttons? also why wouldnt the a/c work either?

[Irving18m]

I have a 1990 s13 and have the EXACT same problem as you. The times i did search for "HVAC help", many times someone told me that it was something behind the dash that swivels to release the different settings?! :( But I do have the same problem, none of my lights work either on the dials. Maybe someone thats not a smart ass can help us! I know of MANY s13's at my local junkyard, just need to know which part i need to look for! Thanks!

[Irving18m]

I have a 1990 s13 and have the EXACT same problem as you. The times i did search for "HVAC help", many times someone told me that it was something behind the dash that swivels to release the different settings?! :( But I do have the same problem, none of my lights work either on the dials. Maybe someone thats not a smart ass can help us! I know of MANY s13's at my local junkyard, just need to know which part i need to look for! Thanks!
I forgot to add that mine works, but its stuck on the defrost setting?! :-/ Do a search for "stuck on defrost" or "heater stuck on defrost"! :confused:

[idlafie]

ok, so a couple of weeks ago my selector switch for the a/c / heat stopped working , you know the buttons on the unit that change it to feet, head, feet and head, defroster etc. they dont work anymore, and neither does the recirculation or A/C button. i have an S13 model and i already tried replacing the unit it self and still no help. The cold hot slider and 1-2-3-4 slider still works. its only the buttons (electrical) the lights don't come on either when you push them...

there was no help in search, any ideas? i tried a new relay, that wasn't it...

Could be several reasons for your problems. You might want to check to see if the wiring harness on the back of your heater control unit didn't become dislodged, (or worked itself loose), from the heater control unit. If that doesn't work, then check the fuses AND test the relays along with the wiring harness. A bad ground to the heater circuit could be the reason why your heater control unit is not working.
If you haven't already done so, download a S13 FSM...Use the SEARCH feature on Zilvia. Sounds like you're gonna need a FSM to troubleshoot your problem.
ID

[idlafie]

I forgot to add that mine works, but its stuck on the defrost setting?! :-/ Do a search for "stuck on defrost" or "heater stuck on defrost"! :confused:

Sounds like the motor servo unit which switches the vent doorss from dash to floor to windshield/defrost has broken or burnt out. Turn your heater or A/C system and flip thru the vent door switches located on the heater control unit. Look underneath your dashboard to the area next to your gas pedal - you should be able to see the motor servo unit located on the side of your A/C - heater system trying to switch between the vent doors. If nothing is happening, then the motor servo is probably fried. Replace that & that should fix your problems....
Looking at a FSM will give you a better idea where the servo motor is located.
Anyhow, hope this helps..
ID