Air Conditioning Won't Turn Off?

[GGill]

Noticed today that my AC compressor comes on when the dash knobs settings are in the "cool" vent position as well as the "cool" AC position, i. e. the fan speed switch in both the clockwise and counterclockwise positions turns on the AC. (saw condensate water dripping out also).



I can hear the compressor switch off only when the fan speed switch is in the 12 o'clock, off position.



Anybody else notice this? Seems as if a switch has failed somewhere along the way...



Thanks, Greg

 

[socal_rattler]

Mine does the same thing, and I have seen other posts on the same subject. It appears (and I need to review my owners manual), that the setting next to the A/C (the one with the snowflake) that shows both upper and lower air is somewhat like a climate control... cool air still comes out. The next setting up which shows only air from the upper vents allows outside air in.

 

[Joe G.]

Greg,



On your '97 you might want to check to see if the selector knob has broken where it slides on the shaft. Mine did that.

 

[dresslered]

On the newer trucks (not sure what years are covered) the only settings which don't utilize the air conditioning are the ones which show "the little man with an arrow at his face" and "the little man with the arrow at his feet. " This can be verified by noticing the lack of a water puddle under the right front tire after stopping.

 

[MidwestMotorman]

ac system

I will second what the guys are saying about the 98 and up trucks.



GGill, make sure the copressor stays 100% off when you have the fan knob at 12 o'clock. The reason I say this, is that if the system gets a little low, you will hear the compressor cycle constantly. It will still dry the incoming air, just not enough to keep the comressor off when the ac or defrost is not working.

 

[RonaldLarson]

The position next to the one with the snowflake (at eleven o'clock) is going to cycle the compressor on when certain ambient temperatures tell it to. When its cooler, it will not cycle the compressor. Sorry I don't know what that temperature is, but it is normal. Kind of like automatic temperature control. Just leave it in that position and your ac will work when it should.

Ron

 

[Joe G.]

I think his '97 has the older setup like my '95 which is pretty old fashioned compared to the '98 and later. I had a trouble like that and the problem was that the selector knob had broken so it would not turn the selector even tho it looked like it did. There may be another problem here, but that's the first place to look. When I went to get one in Sacramento the parts guy just turned around and got one from a box in easy reach. That says something about how good those knobs are. I've been very gently with mine since then.

 

[GGill]

Who knew?

Who knew that a simple thing like AC could be screwed with by the factory to the point that you need directions on how to operate it!!!



The system seems to be functioning OK based on your descriptions. My system definately is different than the 2001 models (no snowflakes) but functions seemingly the same.



No broken knob shaft. I have heard the compressor cycle, but I don't know if the system needs to be charged or if it is in "climate control" mode.



Thanks for the help guys...



Greg

 

[GBall]

Now that you folks are talking about it I wanted to make sure my system is working O. K. If I have my selector switch in the out side air only I still will see some drops under the right side under the truck. Is that right? I do not have the AC selected but will still see some water build up on the ground under the truck after I go in the store for a little. Guys clear this up for me I was under the idea that the AC will cycle all the time even when you have your heater on? Please help clear this up for me. Thanks

 

[MidwestMotorman]

directions

When in doubt, read the owners manual. If still unsure, call on the TDR.



For our 98 and up owners, the ac is only supposed to work in the first three positions and the last two on the knob. The arrow at the feet and the arrow at the face are the only two spots that will not turn on the compressor. The compressor will cycle if the system pressure is low, but this should not happen frequently. If you hear your compressor cycling often, every five seconds or so, it means there is something going wrong in the system. When the system gets so low, the compressor will fail to turn on.



If your cooling core is pressurized, some drying will occur and you will see some water condensing.