Air Conditioning No Clutch On Problem Solved!

Xounlistedxox

Registered User
Problem was the ircm integrated relay control module. Thanks KMT!

Ok, so I've decided to refresh all the o-ring seals on my a/c system and charge it up before it starts getting hot. And to allow the defrost function to work properly for now while its cold.

I've already replaced the o-rings with HNBR O-rings on the back of the a/c compressor x2, the two lines at the condenser 2 on each, those same two lines at the other end(close to firewall) 2 on each, now it appears all I have left is the line at the accumulator by the firewall? Am I missing any that are under the hood?

I will also replace the pressure switch while I'm at it.

Do these a/c compressors typically last a log time, or would it be reasonable to suspect this one may be bad? Every O-Ring I removed was very dry/cracked, so I would suspect that is the reason the a/c stopped working instead of failure of the compressor. The system would hold vacuum only for a couple seconds when I vacuumed the system down before putting the new o-rings in. Also there wasn't any refrigerant left in the system.

Thanks,
Brandon

Update 4-13-14

I replaced all orings finally. Vacuumed down the system for about 30min. Filled the system. Has about 38psi on the low side. The clutch won't engage, & there is very little power going to the compressor wires on the top. I jumped the clutch with a direct 12v wire & it came on right away. I replaced the pressure switch already. I also tried the old pressure switch, nothing happened. Any ideas what could be wrong?
 
Last edited:
I'd expect those o-rings to have dried out because the system broke down, wasn't used for some time and refrigerant wasn't there to keep things pliable.

I replaced the pressure switch and installed o-rings on the condenser tubes when I switched to a narrow condenser in 2010 - vacuumed down and held at least 30 minutes. Last Sept. my A/C clutch reached EOL, so I replaced the entire unit, which came with new manifold o-rings. Vacuum passed muster again.

I found the front seal on the compressor was weeping. Someone put UV dye in well before I got the car, but the only place that ever showed traces was the front of the compressor. It pays to extend system life by being sure to cycle it during the year so everything is well circulated and treated.
 
I'd expect those o-rings to have dried out because the system broke down, wasn't used for some time and refrigerant wasn't there to keep things pliable.

I replaced the pressure switch and installed o-rings on the condenser tubes when I switched to a narrow condenser in 2010 - vacuumed down and held at least 30 minutes. Last Sept. my A/C clutch reached EOL, so I replaced the entire unit, which came with new manifold o-rings. Vacuum passed muster again.

I found the front seal on the compressor was weeping. Someone put UV dye in well before I got the car, but the only place that ever showed traces was the front of the compressor. It pays to extend system life by being sure to cycle it during the year so everything is well circulated and treated.

This car has been sitting since the 90's, so it's needed damn near everything to be replaced. I'm crossing my fingers that the a/c compressor will not follow this theme that the car has going. Once I replace the o-rings and pressure switch I'll give it a shot. I haven't tried vacuuming down the system again yet since I know I still have the o-rings by the accumulator to change.
 
Not sure I'd bother jumping it until I knew for sure it at least had more on the high side than on the low, just to start. If it shows 100+, as an example, then try closing the clutch just long enough to see if the high side tries to climb...be careful. If it does climb, then debug the clutch hot circuit from the fuse and fan switch. It it doesn't, the compressor might be suspect. If it climbs way high, then something else might be blocked.
 
Not sure I'd bother jumping it until I knew for sure it at least had more on the high side than on the low, just to start. If it shows 100+, as an example, then try closing the clutch just long enough to see if the high side tries to climb...be careful. If it does climb, then debug the clutch hot circuit from the fuse and fan switch. It it doesn't, the compressor might be suspect. If it climbs way high, then something else might be blocked.

Looks like over 400psi on the high side
 
ouch...

How much 134a did you put in and what is the outside air temp when testing?

Quoting from elsewhere on the 'net: "With high side pressures approaching 500# you have a restriction somewhere. The three common places for a restriction are the orifice tube, the condensor, and the evaporator."
 
ouch...

How much 134a did you put in and what is the outside air temp when testing?

Quoting from elsewhere on the 'net: "With high side pressures approaching 500# you have a restriction somewhere. The three common places for a restriction are the orifice tube, the condensor, and the evaporator."

I put in three 12oz cans that were oil & 134. The pressure changes depending if I have the compressor on or off. The low side was over 100psi when the compressor was off but around 40 with it on. It was almost 80* today
 
Static low w/compressor off @100 sounds ok for now I think. Any hint of cool air out the vents at all? Is the condenser clean?

If the clutch won't engage using the controls, but you can force it and get 400 on the high side you might have more than one issue.

When you changed the o-rings & pulled a vacuum, did you notice any black junk in the lines?
 
Static low w/compressor off @100 sounds ok for now I think. Any hint of cool air out the vents at all? Is the condenser clean?

If the clutch won't engage using the controls, but you can force it and get 400 on the high side you might have more than one issue.

When you changed the o-rings & pulled a vacuum, did you notice any black junk in the lines?

The air coming out of the vents was pretty cool, not super cold, but decent. There was no black stuff coming from the lines when I pulled vacuum.
 
Do you have an EVTM?

How many volts, exactly, at both the pressure switch and the connector at the clutch? What is the air gap on the clutch?
 
Do you have an EVTM?

How many volts, exactly, at both the pressure switch and the connector at the clutch? What is the air gap on the clutch?

When I removed the connector at the pressure switch it was right around 12v, at the clutch it was less than half a volt. How do I measure air gap on the clutch?
 
If that is the case, I would still think the nearly non existent voltage at the compressor would be a potential problem?

Like I said, I think you still have more than one issue. What is the voltage at the pressure switch? What is the voltage at the fuse under the dash? Do you know how to open the dash where the climate controls are to check voltage at those switches?
 
When you had the system apart, did you replace the dryer?

No, all I have replaced so far is the orings, pressure switch, and refrigerant. That's the same thing I did on my Mustang, Bronco, my old CRX, my old Buick T-Type, & many other cars with great results. I should have known the tbird would be more of a hassle. It has been more of a hassle on every other thing I've fixed than any other car I've owned or worked on.
 
Back
Top