a/c continuosly blows

[2000tahoeZ71]

Signs of a resistor going out are it only works on full blast. If it stays on all the time it likely is the fan selector switch. You used to be able to just buy the switch, it is very easy to replace. You may have to purchase the entire climate control unit now, not sure.

Here they are. http://www.amazon.com/ACDelco-15-72...e=UTF8&qid=1445445397&sr=8-2&keywords=1572275

For some reason that link isn't working on my end. the part number is 1572275 in case it doesn't work for you. 1A Auto has a video on how to do the job, as does Eric the Car Guy. Search for them on youtube if you have any questions.

 

[SunlitComet]

you mean only the high speed blower speed is available and no mid speeds? that could be a blower resistor or a bad blower switch.

 

[2000tahoeZ71]

Yes. In my experience when the blower resistor goes it defaults to high speed and that's all you get. If the motor continuously runs regardless of what positions, it is the switch. Mine would stay on and jump between speeds and even when it would not power the motor, would still power the compressor on. I guess technically it could be both a resistor and the switch, but I would bet the switch is bad.

oops, thought you were asking me Sunlit. My bad.

 

[rs657f]

Gotcha, that makes sense. All none of the buttons or knobs on the panel work. I was going to order both to be on the safe side. It does just blow all the time on high no matter what i do. Im going to aim for the switch control panel and then hit the resistor if nothing happens. I will follow up once i install those parts too. Thanks for the help gentlemen.

 

[SunlitComet]

quick function check. with blower switch off, does the temperature door move as commanded while other functions are disabled? if nothing works including any fan speed check i/p fuse. crap, what year is yours so i am looking at the correct data for further analysis.

 

[rs657f]

It's a 96. Literally soon as I turn the key on its full blast a/c nothing can be adjusted from the control panel. It doesn't go off until I turn the car off. I was hoping it was just that resistor but I don't know. When I pull the dash fuse it does cut off

 

[SunlitComet]

if you mean the blower at least is full blast when you turn on the key and then you need to replace the blower switch before continuing. by design and your statement i see that your blower switch is somehow shorted inside causing the hi speed relay to bypass lower speeds and connect the blower directly to battery source.

www.amazon.com/ACDelco-15-72275-Original-Equipment-Conditioning/dp/B0012P2KB4/

 

[rs657f]

nice so this piece is on the back of the control panel? I could just buy this without having to get the whole panel. One more question. I noticed the buttons on the a/c panel itself do not light up when i press them. Would it jus tbe safe to replace the whole panel?

 

[2000tahoeZ71]

If the controls will not switch from floor to vents, defrost or control heat, then yes I would replace the whole unit.

 

[SunlitComet]

try the switch first it also functions to all controls except temperature door. if that is disabled as well then the control head it may be. the lights on others may just be disabled because of bad blower switch or just burned out.try blower switch first.