Air conditioner not working?

TEDHED

MEMBER
1998 BUICK LESABRE
6 CYL
2WD
AUTOMATIC
120,000 MILES

AC clutch will not engage. Not sure if a lack of freon will cause this to happen or if that will just result in the unit quick-cycling. Checked corresponding fuse in fuse box beneath steering column. Fuse is good. Not sure where to start. Manual says there is another fuse set on the passenger side. Haven't been able to locate that. Fans, temp sets, all that stuff works in the control panel. I did notice that the fan cycles high and low all the time even when not in auto mode.

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

AC clutch will not engage. Not sure if a lack of freon will cause this to happen

This video will show you how to add

https://youtu.be/uZrQCGwXfek

Is you car's air conditioner blowing warm air only and no cool air? Your A/C cooling problem could be caused by any of the following:

Your A/C system may have lost its charge of refrigerant, or the compressor may not be engaging when you turn on the A/C, or the blend air door inside the HVAC unit may be stuck in the HEAT position so no air goes through the A/C evaporator.

Start with the compressor. Does it engage when you turn on the A/C?

If so, the compressor is working and the A/C system probably contains enough refrigerant to make cold air, so the problem is inside the HVAC unit. Replace the motor that controls the blend air door (this is a difficult job and best left to a professional since it involves tearing apart the HVAC unit -- about an 8 to 10 hour job!).

If the compressor does not engage when you turn on the A/C, see if it will run by jumping the compressor clutch wire directly to the battery (use a fused jumper wire). If the compressor works when you jump it, and the A/C blows cold air, the system contains refrigerant and the fault is likely a bad A/C compressor clutch relay or a bad clutch cycling switch or pressure switch.

If the compressor does not engage when you jump it, the problem is a bad compressor clutch.

If the clutch engages but the compressor does not turn (the belt will start to slip and squeal), the compressor is loced up and you need a new compressor.

If the compressor clutch engages and turns the compressor, but the A/C still does not blow cold air, the system is probably low on refrigerant and needs to be recharged. If you Have an A/C gauge set, hook it up and see if the system has any pressure.

If it is out of refrigerant or is low, check for leaks, then have the A/C system vacuum purged to remove air. After the air is out, it can be recharged with the specified amount of refrigerant. It is important to get any air out as this will reduce cooling efficiency and may make the compressor noisy.

My advice to you if you know nothing about A/C service is to find a repair shop that specializes in A/C repairs and let them fix your cooling problem for you. Today's A/C systems with automatic climate control are very complex and reuire special tools and know-how to diagnose and repair.