AC Clutch not engaging

[Ozymandias]

Don't mess around with it if you get decent cool air.

 

[Zoomschwortz]

More pictures
Definitely got hot.

 

[Zoomschwortz]

O/S temp 74f
Engine not running 83 psi

Engine @ 1,000 rpm
Low 24 psi - High 205 psi

 

[Ozymandias]

Perfect numbers, leave it.
Pressures are in the range of mine with weighed in fill of R134a.

 

[06 Dodge]

I recall back in 1975 when installing aftermarket ARA units on Dodge chassis this was back when we had R12 if once ac was up an running at 70 if we didn't see a temp 39 or under we got chewed out for it not cooling properly...

 

[Ozymandias]

R12 goes lower then R134a.
40° is a good Value for a modern AC.

 

[Zoomschwortz]

Thank you for this information, sounds like I'm where I should be with pressures and temp.

Trying to figure out why the coil and clutch got cooked.
Is it possible for the coil to get weak, allowing the the clutch to slip?
It never gave any hint of going bad, no funny noises, bad smell and always had cool temp

 

[jghflys]

Engine @ 1,000 rpm
Low 24 psi - High 205 psi

Looks good to me. The clutch is metal to metal it wears and gets loose. Surfaces have a blue color indicating overheating due to slipping.

My manual has this burnishing process for a new clutch. I do not know if it applies to your clutch brand. I did not do it on the Sanden clutch I replaced because I did not know about it at the time.
"After a new A/C compressor clutch has been installed, cycle the compressor clutch approximately twenty times (five seconds on, then five seconds off). During this procedure, set the A/C-heater controls to the A/C Recirculation Mode, the blower motor in the highest speed position, and the engine speed at 1500 to 2000 rpm . This procedure (burnishing) will seat the opposing friction surfaces and provide a higher compressor clutch torque capability."

 

[Ozymandias]

Good information here, thank you. Never heard of that.

 

[jghflys]

Never heard of that.

Grasshopper mowers I have owned have a similar procedure for burnishing the clutch. They even recommend cycling the clutch 5 times after a long period of inactivity. Probably applies to most metal to metal clutches.

 

[Tuesdak]

Thank you for this information, sounds like I'm where I should be with pressures and temp.

Trying to figure out why the coil and clutch got cooked.
Is it possible for the coil to get weak, allowing the the clutch to slip?
It never gave any hint of going bad, no funny noises, bad smell and always had cool temp

Improper air gap due to wear etc. Air gap too close and dragging lightly. Bad fan clutch allowing high head pressures that overcame the holding power of a worn or oil contaminated clutch, compressor starting to lock up, liquid slugging on startup and clutch isn't able to get the compressor spinning... Once the clutch isn't able to spin the compressor it burns up really fast - like an on ramp to a freeway in distance fast. Had a vehicle that would kick out the compressor on WOT and then expect it to kick the compressor over when you got out of it. Worked till the one time it didn't and I cut the belt as the bearing also failed (balls on one side vibration vs. locking up.) in the burn-up.

Your compressor shaft seal is on borrowed time because it also got this hot. Just keep it in mind and inspect the compressor clutch for oil from time to time. It should be the first suspect in a system leak in the future aside of the pressure relief valve blowing refrigerant off as noted before.

If the coil will pull the clutch in: it's strong enough to hold due to the decreased magnetic distance when the clutch snaps together. Can a intermittent bad ground or other low voltage condition weaken the field: yes. Is it the first thing I would look for: no.

 

[Zoomschwortz]

Improper air gap due to wear etc. Air gap too close and dragging lightly. Bad fan clutch allowing high head pressures that overcame the holding power of a worn or oil contaminated clutch, compressor starting to lock up, liquid slugging on startup and clutch isn't able to get the compressor spinning... Once the clutch isn't able to spin the compressor it burns up really fast - like an on ramp to a freeway in distance fast. Had a vehicle that would kick out the compressor on WOT and then expect it to kick the compressor over when you got out of it. Worked till the one time it didn't and I cut the belt as the bearing also failed (balls on one side vibration vs. locking up.) in the burn-up.

Your compressor shaft seal is on borrowed time because it also got this hot. Just keep it in mind and inspect the compressor clutch for oil from time to time. It should be the first suspect in a system leak in the future aside of the pressure relief valve blowing refrigerant off as noted before.

If the coil will pull the clutch in: it's strong enough to hold due to the decreased magnetic distance when the clutch snaps together. Can a intermittent bad ground or other low voltage condition weaken the field: yes. Is it the first thing I would look for: no.

Thank you, Lots of good information.

In all of my studying before installation, I did find the break in procedure and did do the 5 second on-off for 20 cycles @ 1500 rpm.
I set the clutch gap @ .020"

After seeing many complaints or recommendations of 2 sets of hands for putting the serpentine belt back on, I used a couple Erwin Quick Clamps to hold the belt onto a pulley after the compressor and before the tensioner. This worked great at keeping the belt on all of the pulleys after removing the compressor pulley.

I'm going to buy an entire AC rebuild kit with new compressor and have it on hand in case the compressor dies or the systems starts leaking sometime in the future.

Thanks again to everyone for your help
Ken