No A/C at idle? compressor cycles rapidly, or stays disengaged....works at speed

[paulkeith]

subject says most of it.

A/C works fine at speed, very cold.

At idle, the compressor cycles rapidly (few times in a few seconds) and then just stays disengaged.

No A/C trouble or work since I've owned it, ~3 years.

Help? I'm thinking low charge?

Paul

 

[bbressler]

What year model is your truck?

There is a wire connection at the back of the compressor that tells the compressor to kick on, I've had trouble with that connector lots. Try wiggling that connection and see if that doesn't make it kick on. Mine started out like you are describing, and finally quit altogether. I replaced that pigtail and it worked again for about a year, and now it's coming back again.

 

[paulkeith]

woops, didn't include my sig by default. truck is a 02 7.3.

I did wiggle the clutch connector thinking the same thing, but if it works fine at higher RPMs i was doubtful that would be the culprit.

Thanks,
Paul

 

[BIG JOE]

What year model is your truck?

There is a wire connection at the back of the compressor that tells the compressor to kick on, I've had trouble with that connector lots. Try wiggling that connection and see if that doesn't make it kick on. Mine started out like you are describing, and finally quit altogether. I replaced that pigtail and it worked again for about a year, and now it's coming back again.

X2 Paul. I've had the same issues with that pressure switch (I'm told thats what it is) 4-5 times. I just diconnect it, clean the contact, plug it back to gether.. works Great.. till the next time.

Wiggle/clean ALL the A/C connected plugs & switches.. for that matter ??

Joe

 

[paulkeith]

I hear what you guys are saying, and I'll check it out....

When you were having these issues, were they RPM dependent like my case?

Thanks,
Paul

 

[95_stroker]

Your refrigerant charge may be low or your condensor may be dirty causing either a low suction pressure or a high discharge pressure.... need to get a set of gauges hung on the system to properly diagnose it.

 

[paulkeith]

roger that, my work's auto club has a full set of a/c diagnostic and repair tools, i'm planning on hooking the gauges up tomorrow afternoon.

 

[BIG JOE]

I hear what you guys are saying, and I'll check it out....

When you were having these issues, were they RPM dependent like my case?

Thanks,
Paul

I kinda thought it was RPM dependent but then the A/C would cut and out at cruise RPMs and stay out, then at idle.. and sometimes it would work No Problem.

Hooked up my gauges when I got home.. Full Charge.

Then I started wiggle'n anything HVAC... found I could control the compressor clutch by wiggle'n the pressure switch connector plug. took it apart and cleaned up the pins. Worked fine til the next time

An Automotive A/C guy I know sez the connector thingy is Known for doing that. Prolly a Mili Amp/Mili volt thing

Try Wiggle'n that connector.. See what you git

Joe

 

[paulkeith]

right on. thanks.

 

[paulkeith]

you guys fricken nailed it. pushed on the clutch electrical connector directly behind the pulley and the compressor would engage and stay engaged. as soon as i let go, it would disengage or flutter.

cleaned with acetone and reconnected, icebox all the way to work this morning.

Thanks!!!!!!!