chipster1977

I have 2005 Civic LXG

A/C works great except it never shuts off, whether the A/C button is on or not. My mechanic has looked at it twice and can't find the problem??? He thinks that it might be a defective button/ switch on the dash.

In the summertime the A/C runs until it basically freezes up and vapour comes out of the vents and then nothing comes out of the vents at all.

Since then we replaced the relays with ones from a different car. No change.

I pulled the A/C relay because I live in Ontario and its November. Now my cooling fan runs non-stop, even at cold start up. Tonight I looked at it and I'm pretty sure the compressor fan is running non stop as well.

Has anyone experienced this issue? Or could clue me in to the possible issue.

ezone

Find a mechanic that is GOOD with electricity. This should be simple to figure out if one can follow a wiring diagram and figure out what and how to test with not much more than a wiring diagram and a scanner.

A problem like you describe (always present) should be EASY to figure out, but one needs to be proficient with electricity and have understanding of the systems involved first.


Electricity is like the final frontier of car repair. Many mechanics just never grasp the concepts.

I'm looking at USA diagrams here, I hope Canadian is similar....

Disconnect the A/C pressure switch, or disconnect the 3 wire connector from the compressor.

If the fans stop running all the time, this probably indicates a bad HVAC control unit (or a wiring problem causing the same effect). Reconnect whichever you just unplugged.

Pull out the HVAC panel from the front of the dash.
Disconnect the HVAC controller plug and see if the AC shuts off now. (HVAC controller bad is common, but your failure isn't the normal symptom I usually see.)


If disconnecting the compressor connector or pressure switch connector did NOT get the fans to stop, then you could have a multiplex controller problem or something else....then I would go testing.....following a wiring diagram with a voltmeter, and using a scantool to see what the PCM is doing, since it has control of the compressor clutch relay.

HTH

chipster1977

Thanks for the reply.

The 3 wire plug for the compressor is pretty hard to reach. Is there an easier spot to disconnect to try this?

ezone

IDK, I never considered if it would be easy or not. I just said to disconnect as a test.

The way it is wired (according to the diagram), disconnecting either one should cause the exact same things to happen.

A wiring diagram would show the "why" part of this.....or it might look like spaghetti dinner to most people.

HTH