Mechanics

COMPRESSOR CLUTCH INTERMITTENT ENGAGEMENT

2005 Toyota Sienna

Air Conditioning problem
2005 Toyota Sienna 6 cyl Two Wheel Drive Automatic 105000 miles

The last two days the a/c on my 2005 Sienna has not worked. When I looked at it last night, the ac worked fine. I let the van run for five minutes with no issues. This morning, I drove the van to get a new alternator belt, which was original to the van, and teh ac did not work. I let the van cool so I could replace the belt: about two hours. When the belt job was done, I hooked a low pressure ac guage to see if teh coolant was low. The compressor kicked in and ran well. The low side pressure was 50 psi so I let it run for another 3 minutes with no issues. It was 90+ degrees outside. I shut the van off and the ac has not engaged the remainder of today. I marked the clutch and it has not turned. It appears the compressor clutch is not engaging.

I fiddled with the coils under the hood. Appears there are two: one for the AC and one for the clutch? I actually swapped the heater and ac cubes with no results.

I pulled the connector to what I assume is the pressure sensor. The engine slows and the fans at the radiator shut off when it is not connected.

What else can I check? I an not sure what I can jumper to get the clutch to engage.
Avatar
Tissueman
August 14, 2010.



Hi tissueman,

Thank you for the donation.

A low pressure reading of 50 psi is rather high. Was the freon ever topped up recently?

The fans working and turning off when the pressure switch connector is unplugged indicates the A/C circuit is working but the compressor is not turning on.

Check the wire to the compressor for battery voltage. If voltage is present, the compressor clutch is faulty.

You can use a remote battery voltage source to connect to the compressor to test if it clicks on.


KHLow2008
Aug 14, 2010.
Thank you for the reply.

The ac has never been touched since we bought the vehicle new.

I just tried the van ac. It worked. I drove about two miles and it failed. The clutch disengaged again. I will try the connection in the morning.


Tiny
Tissueman
Aug 14, 2010.
You're welcome.

I have sent you the compressor circuit diagnostic information.

Hope they are helpful.

Let me know if you require any help on the diagnostics by posting your replies here.


KHLow2008
Aug 14, 2010.
Thank you for all the help. Conclusion: the clutch was bad. Replaced it and the system now works fine.


Tiny
Tissueman
Aug 19, 2010.
You're welcome.

Glad to know you have fixed the problem.

Thank you for using 2carpros and have a gret day.


KHLow2008
Aug 20, 2010.
Did you replace the clutch yourself? I have the same symptoms on my 2004 Sienna. I found the clutch on ebay for $100, but am unsure if it's a user replaceable part.


Tiny
Kaufmade
May 31, 2011.
Replacement of the clutch requires discharging the gas so I would not say it is a DIY job.


KHLow2008
May 31, 2011.
KHLow2008, Thanks for the quick response!

The shop that told me the clutch is bad has already drained the gas. However, if replacing the clutch requires disassembly of the compressor, it's probably more than I care to tackle. I was hoping that replacing the clutch is a simple matter of loosening that center bolt.

Thanks again,
Dave


Tiny
Kaufmade
Jun 1, 2011.
It is not as simple as that but neither is it too difficult.

REMOVE MAGNET CLUTCH ASSY

a) Place the compressor and magnetic clutch in a vise.
B) Remove the bolt, the magnet clutch hub and the magnet clutch washer.
C) Using a snap ring expander, remove the snap ring and the magnet clutch rotor.
D) Remove the screw and disconnect the connector.
E) Using a snap ring expander, remove the snap ring and the magnet clutch starter.

INSTALL MAGNET CLUTCH ASSY

a) Fit the parts as shown in Fig. 145 and install the magnet clutch starter.

B) Using a snap ring expander, install a new snap ring with the chamfered side facing up.

C) Install the screw and connect the connector.

D) Using a snap ring expander, install the magnet clutch rotor and a new snap ring with the chamfered side facing up.

E) Install the magnet clutch washer and the magnet clutch hub.

NOTE: Do not change the combination of the magnet clutch washers used before disassembly.

F) Install the magnet clutch hub and the magnet clutch washer
with the bolt.

Torque: 18 N.M (183 kgf. Cm, 13 ft. Lbf)


KHLow2008
Jun 1, 2011.
KHLow2008,

Thanks for the great instructions. I just may tackle this project.

Have a great summer--Keep cool: )

Dave


Tiny
Kaufmade
Jun 1, 2011.
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