air conditioning problem

[kodi3482]

so i have a 91' legacy 2.2l, 98k miles. ac system is still the r-12. no reason to change it since its such low miles and the ac blows at 36-38 degrees.. its full on freon, and everything is crazy clean.

now the problem.. most of the time the ac will not turn on period. doesn't matter what button i push, or where its set. i've checked relays, fuses, etc. with the car running and ac on (not working). and at random i can switch it off and back on and it will kick on and work fine, sometimes for an entire 200 mile trip, or it will just stop workin after about 15 min and not decide to work again for anywhere from 30 seconds to a few hours.. it seems totally random as when it wants to work and doesn't.. beings i can switch it on and off several times and sometimes it will come on (most of the time not) i am leaning towards the switch panel. but it would be a throw a part at it and cross fingers.

any ideas?

[DevC]

Mine behaved the same when it was overcharged, it was tripping the pressure safety switch, so if the clutch/wiring etc checks out, then you may need to check your pressures.

[Legacy777]

I would definitely recommend checking the pressures in the system, but it's good chance the HVAC control unit may have cracked solder joints that need be repaired. Here's my thread with some more info.

http://bbs.legacycentral.org/viewtopic.php?f=10&t=1142

[abigaillozano]

Could it also be that the very low miles on it has simply made the AC stop working? Did the thread starter break in the car way back when? I remember an uncle of mine didn't break in his car and after a few years of driving, his AC was so weak that it was better to simply roll down the windows. Take note that even though everything was fine with the HVAC system.

imo, you just didn't use the car so much that the AC died on you :p

anyway good luck to you and hope you solve it!

[DevC]

Could it also be that the very low miles on it has simply made the AC stop working? Did the thread starter break in the car way back when? I remember an uncle of mine didn't break in his car and after a few years of driving, his AC was so weak that it was better to simply roll down the windows. Take note that even though everything was fine with the HVAC system.

imo, you just didn't use the car so much that the AC died on you :p

anyway good luck to you and hope you solve it!

Probably just lost its charge.

[mcbrat]

there's a back-pressure valve that can go bad too... I think that's what's wrong with mine, but I haven't had time to check it out...

http://bbs.legacycentral.org/viewtopic.php?f=5&t=44423

[Omega79]

I'm betting it's the typical cold solder joint issue like 777 mentioned. Seen it a couple times now especially considering it sometimes works and when it doesn't it doesn't matter what button is pressed...

[kodi3482]

well i dug into the ac thermoswitch in the heater box. when the ac is running and it clicks off, i can basically unplug and plug the thermoswitch and the ac will come back on and work fine.. i've bypassed the thermoswitch now, there was a writeup i found that showed which wires to jumper.

anyways, with it bypassed the ac works awesome now.. i know the thermoswitch is supposed to shut the ac off if the evaporator gets too cold. well mine was apparently shutting it off before it really got cold.. everything else is in good working order, i had a local shop evac and recharge the system just to make sure there was no moisture, etc in it.. everything checked out good, wasn't low, etc.. they were surprised since the cars so old..

thanks for all the tips

[Legacy777]

Did you put a thermometer on it? Either the thermo switch is bad, or it's shutting off for a reason and you need to try and figure out what's wrong with it.

[Omega79]

Huh, I had the same part go bad but different symptoms. Swapped mine out for one from my "eventually will be a racecar" and it works great.

[kodi3482]

Did you put a thermometer on it? Either the thermo switch is bad, or it's shutting off for a reason and you need to try and figure out what's wrong with it.

yup, its deffinitely was not a "too cold" problem.. it wouldn't kick on even when it was 95 degrees.. and xsometimes if would stay on and work great.. was totally random..

the thermoswitch was just bad.. been running with it bypassed and everythings happy.. no freezing, etc..

[Legacy777]

Ok, well at least it's working then.