A/C Clutch Not Engaging When On

[SilverBill68]

I have a 2005 2500HD Silverado that when the A/C is on the clutch does not engage. It will engage for a short period of time when the vehicle is started but not when the A/C is in the O N position. Any suggestions (with required tools preferably)?

 

I figure I should offer some more info so here it is. While noting the above condition, the A/C temp was set at 65 with an outside temp of 90 deg. I checked both fuses but have not check the small gray block (relay?) in the fuse panel. The clutch will engage at start-up but as soon as the enging is started the clutch disengages. The service manual calls for checking the High and Low pressures of the system but I don't have the A/C computer they show. Any clue would be better than the none that I have.

 

Thanks,

Bill

[KICK]

need to check the refrigerant, just like they said.

 

cycling clutch systems read low side pressure to determine cut-in and cut-out of ac clutch.

 

too low a pressure and clutch cuts off, being low on refrigerant causes same effect you described.

[SilverBill68]

need to check the refrigerant, just like they said.

 

cycling clutch systems read low side pressure to determine cut-in and cut-out of ac clutch.

 

too low a pressure and clutch cuts off, being low on refrigerant causes same effect you described.

 

<{POST_SNAPBACK}>

 

 

 

Thanks, I'll give it a try. More to follow.

[Highmiles]

It seems a little new for this problem, but I have had my pressure switch go out before. It is a threaded plug on the drier near the firewall, usually with 2 wires to it. I believe that you can jumper across the connector to check to see if the compressor will kick on.

 

However, it could be that the switch is good and there is a genuine low pressure situation, but this might give you a clue.

[KICK]

It seems a little new for this problem, but I have had my pressure switch go out before.    It is a threaded plug on the drier near the firewall, usually with 2 wires to it.  I believe that you can jumper across the connector to check to see if the compressor will kick on.

 

However, it could be that the switch is good and there is a genuine low pressure situation, but this might give you a clue.

 

<{POST_SNAPBACK}>

 

 

 

 

your right. I've had the same problem.

 

if you have gages and pressure in system and it wont engage the clutch, jump the switch and you will know for sure.