A/C compressor clutch will not engage?

ZOHMOM

MEMBER
2008 HONDA ODYSSEY
3.5L
6 CYL
2WD
AUTOMATIC
194,000 MILES

Clutch for compressor will not engage. Jumped across #1 and #4 of pressure switch. The compressor clutch kicked in. I have a full charge of r-134a (48 psi low side.195 psi high side. About 80 degrees F). Purchased a new switch. Replacement required evacuating system. Installed switch. During recharge, Clutch intermittently stopped and would not reengage. Jumped across terminals #1 and #4 again. Still did not engage. Shut engine off and gave it some time to settle. Came back, started car and turned on a/c. Clutch engaged. Continued with charging. Made it to 42psi/185psi and clutch stopped again. Jumping switch made no difference. BTW, condenser and radiator fans ran constantly. Shouldn't these pressures be sufficient ton operate system?

Tuesday, April 22nd, 2025 AT 2:13 PM

1 Reply

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

Hi,

Based on the issue's description, it sounds like you are not getting a good power supply. I'm not sure what all has been done yet, but certainly it could be something as simple as a fuse not making good contact or even the clutch relay.

When the compressor clutch isn't operating, check to see if there is power to the clutch. If there is no power, switch the clutch relay with a known good one having the same part number to see if it changes. Also, remove the relay fuse and check for a connection issue or corrosion.

The relay and fuse are both in the under-hood fuse box. If you have no power at the clutch and the fuse and relay are good, jump terminals 30 and 87 to see if there is power to the compressor.

Here is a link you may find helpful when testing a relay and relay circuit:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Let us know what you find.

Take care,

Joe

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