Air Condition Won't Come On

[Argyll]

Hi All,

 

Was hoping someone who knows air conditioning could point me to some basic things to troubleshoot before I take my truck to have the A/C checked.

 

1993 Chevy C1500 W/T 2WD V6 5spd Manual, 180K miles. Air conditioning has worked perfectly since the day I bought the truck new, up until this last week. Since it's beginning to warm up here in the South, I decided to turn on the A/C to test it the other day.

 

A/C fuse in fuse box is good. A/C indicator letters above the A/C push button dash switch come on in the display. I hear the click of the relay behind the dash/glove box. However, the compressor will not come on, the clutch won't engage. I can free turn the clutch with my hand with enginge off so it doesn't appear to be jammed or bad mechanically. I did replace the relay behind the glove box, but compressor still doesn't come on.

 

There is also a problem with the recirculation actuator box thing (don't know the name of this). It's the thin black box mounted to the side of the blower box under the dash on the passenger side that opens or closes the flap to either let in or close off the outside air. It was making a clicking sound becase it wasn't opening or closing the flap fully and seemed like it just kept trying to turn constantly. I did get it working again after taking it apart. One of the gears inside (4 gears total) had a tooth missing and it was hanging on it. I rotated the gear and it's working again. Would this part malfunctioning cause the A/C compressor not to come on?

 

Anyway, is there any other basic switches/fuses/relays or other common things that cause A/C problems I can check that would be the culprit here before I take it in to a shop? If you have suggestions, please indicate the location of it in the truck so I can find it because I'm not an A/C expert. Thanks for any suggestions.

[ken1mod]

If it is below about 40 degrees the compressor will not run because of the low pressure switch. Check this switch, it is on the accumulator. This switch will also sence low ref charge. I hope you checked system when it was 20 degrees outside, maybe no problem at all. Do not replace anything unless proven bad.

 

Your problem is likely in this area.

 

Ken

[Argyll]

If it is below about 40 degrees the compressor will not run because of the low pressure switch.  Check this switch, it is on the accumulator.  This switch will also sence low ref charge.  I hope you checked system when it was 20 degrees outside, maybe no problem at all.  Do not replace anything unless proven bad.

 

Your problem is likely in this area.

 

Ken

 

<{POST_SNAPBACK}>

 

 

 

Thanks Ken. I'll check that when I get home tonight. I didn't notice a switch on the accumulator, but I'll look again. I tried running the A/C when it wat about 55-60 degrees out, it was at night this past Saturday.

[97C1500&84Z28]

You may be low or out of refrigerant.

[JAMIEZ71]

If your refrigerant is low the compressor will automatically shut off to keep you from burning it up. If you disconnect the positive battery terminal for at least 5 minutes and the reconnect and start your truck the compressor should kick on if it isn't really low on refrigerant. Make sure when you start the truck your ac is on max and turned to as cold as it can be. This is what I had to do to my work truck this past summer. When you get some refrigerant you may need to people to do this. It will only accept fluid if the compressor is running so you may need to dissconnect it and then hook your can to it and be ready. Have someone else start the truck and hit the trigger on the can to start filling it. It's best to buy a can of refrigerant with the gauge on it. Don't overfill it because it won't cool as good. My uncle is a GM mechanic and that's where I got that little trick from. Hopefully your truck has been switched over to r134a so you can do this yourself.