A/C clutch not engaging

SWEETLEAF

MEMBER
1999 HONDA ACCORD
V6
FWD
AUTOMATIC

I'm not getting power to a/c clutch, fans are working, all fuses, relays and pressures are good. I can jump the relay for clutch and the compressor works, and when I ground the wire from ecm to relay it works. Someone before me looked at it and said it was the ecm, I'm not convinced just yet, but I have no wire diagram or pin out for ecm. Any and all help is greatly appreciated thanks. Also do I need to reprogram the ecm if I get one from junkyard.

11 Replies

WRENCHTECH

MECHANIC
20,761 POSTS

The ECM is not going to be the problem. It is intentionally not turning it on because it is not satisfied with something else in the system. It could be one of the pressure switches but it needs to be troubleshooted using a wiring diagram.

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Wednesday, June 10th, 2015 AT 9:21 AM

DON PIPOLY

MEMBER
4 POSTS
1994 HONDA ACCORD
2.6L
4 CYL
2WD
AUTOMATIC
257,000 MILES

My A/C clutch won’t come on. Condenser fan comes and I can jump relay A/C comes on.

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Monday, August 12th, 2019 AT 12:06 PM (Merged)

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Welcome to 2CarPros.

Have you confirmed the system isn't low on Freon? Also, have you tried replacing the relay?

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

https://www.2carpros.com/articles/air-conditioner-how-to-add-freon

Let me know.

Joe

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Monday, August 12th, 2019 AT 12:06 PM (Merged)

DON PIPOLY

MEMBER
4 POSTS

Has good Freon PSI, tried new relay.

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Monday, August 12th, 2019 AT 12:06 PM (Merged)

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

Hello,

Can you check fuse #34 for power? here is a guide to help us and the fuse location as well as the air conditioner wiring diagrams so you can see how the system works:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Check for power at the fuse. Check out the diagrams (below). Please let us know what happens.

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Monday, August 12th, 2019 AT 12:06 PM (Merged)

DON PIPOLY

MEMBER
4 POSTS

Ken, thank you.

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Monday, August 12th, 2019 AT 12:06 PM (Merged)

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

No problem, please let us know what the fix is.

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Monday, August 12th, 2019 AT 12:06 PM (Merged)

DON PIPOLY

MEMBER
4 POSTS

It was a blown #34 fuse

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Monday, August 12th, 2019 AT 12:06 PM (Merged)

JABENNETT1965

MEMBER
1 POST
1994 HONDA ACCORD
4 CYL
2WD
AUTOMATIC
208,000 MILES

I've a 1994 Honda Accord EX my a c clutch on the compressor won't come on the condensor fan won't come on also. I've checked the fuses inside the car in the fuse box I've also checked the fuses on the pass. Side under the hood and rhey're also good. I've let someone checked with gauges to see if it had freon in it and was full. Now if I run a wire to the connector that goes to the clutch and the condensor fan taking out the relay and touching the pins with the wire that coming from the battery(pos) post the compressor clutch and the condensor fan would come on.

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Monday, August 12th, 2019 AT 12:06 PM (Merged)

KHLOW2008

MECHANIC
41,814 POSTS

Hi jabennett1965,

Here is a schematic of the AC condenser fan and circuit. Seems the relay is not being grounded by the ECM to control the AC clutch and fan relay.

At the ECM A12 terminal, ground it to test if the clutch relay works. There are known issues with the ECM grounding circuit for the AC compressor.