AC Climate Control

[kingkon]

I bought this truck a couple of months ago and had it parked. Yesterday I picked it up from where I had it stored. The couple of times I've driven it it has been good. The AC has worked correctly. Last night on my way home, from a 140 mile trip, the AC started first blowing out of the floor then after a while not cold. The climate control still changes the blower speed, but the AC and Recirculate LEDS are not lit after being lit when I first started the trip. The knob to select where the air is to come out from doesn't do anything either. Any ideas? Truck is a 96 2 door.

 

[SunlitComet]

suspect a fualty blower speed switch if all but the temp functions are disabled on any running fan speed.

 

[kingkon]

All the blower speeds work except high. It only blows hot so I wouldn't know if the temp knob makes a change and the knob to change where the air comes out of doesn't do anything, it only blows out of the floor. I searched around and I think it's the whole climate controller. I found this: http://www.silveradosierra.com/how-...k-series-trucks-hvac-control-unit-t77522.html
Mine fits the description in Problem 1

 

[SunlitComet]

and problem one is the blower switch as it says. the transistor issue is rare so do you have a voltmeter?

 

[kingkon]

Yes

 

[kingkon]

I took this picture of the top of the climate controller today. You can see a burnt spot on the left of the board.

 

[SunlitComet]

on the inline connector in the back of the control head the dark green wire next to a black one should have 12v on that wire only when the blower switch is in the off position only. and have no voltage on it when a speed is selected. key must be on and control head fully plugged in. do not short out the control head. it is easy to do.

 

[SunlitComet]

View attachment 60383 I took this picture of the top of the climate controller today. You can see a burnt spot on the left of the board.

to late it has shorted out. get a new one from amazon with the switches included. which one depends on year and whether you have a rear defroster.

 

[SunlitComet]

wrap up the antenna connector before putting the new one in and check for loose metal around the area as well.

 

[kingkon]

Thanks. Another question, I won't be using the rear defroster. The current climate controller has the defroster button, will one without the defroster button work?