A/C Compressor Won't Engage
 

I press the A/C button and it turns green, but the A/C never turns on. The compressor doesn't even engage nor do the cooling fans start spinning.

Anyone ever have this problem and fix it?

this is totally a guess, but could it be related to the AC clutch?

Re: A/C Compressor Won't Engage
 

Well, if the cooling fan doesn't even come on, then I would check the no. 20 fuse under the hood and the no. 14 fuse under the dash first. Also, check the evaporator temperature sensor. These will affect both the compressor and fan. It could be that the compressor and condenser fan are failing independently at which case, start checking the relays, the connections to the ECM for continuity, the compressor clutch and the a/c pressure switch.

Cim

Fuses and relays are alright. Do you know where the evap sensor is located?

The system could have leaked out. The low pressure cut off switch will prevent the fans and compressor from running.

Problem turns out to be a stuck expansion valve. There were no leaks in the system, but of course, now it needs to be recharged after the valve is replaced. Thankfully Honda is getting the new part to me today. I'm selling the car tomorrow!

A stuck expansion valve???? Ok..... that's different. Usually that will not prevent the system from running, just from getting cold.

You're right Tinman...I got a call from Honda last night saying that it didn't fix the problem. Whatever diagnostic equipment they use "told them" the problem was with the expansion valve. Now they've actually told me that they have no clue what's wrong with the system. I'm not even sure if the system is leaking. I asked if they checked for a hole in the condenser, and they replied they had.

So much for selling my car today...at least they gave me a brand new Expedition to drive in the meantime. Damn, I missed having RWD.

I can't believe that the techs at your Honda dealer can't diagnose something as simple as an AC system. It's really sad.
A while back I posted about an alternative refrigerant that I am using in MY civic with great results. I can run the AC all the time, with very minimal load on the engine. It runs on less than half the pressure or R134, and gets COLDER.
Anyway, The AC may not start because: The compressor clutch is electrically open, so it won't engage. The low pressure safety cut-off switch is bad, OR the system has indeed leaked out so the switch won't engage. Again, it won't run. Lastly, either the teperature sending unit to the ECU is bad, or the 12volt line from the ECU is bad.
There IS an issue on some civics, now that I think about it. The ECU is faulty, and won't engage the AC. As you know, the ECU turns off the AC when you step on it hard in order to conserve power. Some were flawed, and simply would not turn the AC back on. Lastly, the fuse. So obvious, that it should have been checked right away.
A good tech could figure this out in 10 minutes.
That's probably why I DON'T take my car to Honda. I do all my work myself.

I usually do most of the work myself, but this is my first Honda and luckily I still had a bit of warranty left. I won't even pretend to know much about the AC systems on any car though.

Anyway, Honda called me yesterday afternoon. They called Honda's "help-line" and it recommended they replace the "thermal coupler". We'll see if it fixes the problem, but when I brought it in I had a feeling the problem was electrical. I know the fuses and relays are alright...but who knows about the sensors, ECU, etc. Shouldn't the check engine light come on with a faulty sensor?

In the meantime I'm really starting to like this Expedition.

The AC won't turn on below a certain ambiant temperature (when it's really cold outside). So it could be a faulty temp sensor.

Tinman, you using freon?

gearbox, I am using an R-134 replacement made by envirosafe. It can be run in BOTH R-12 and R-134 systems. It runs at much lower pressures and gets a lot colder than R-134, and slightly colder than R-12. It also won't cause the "black death" that is common in R-134 systems. R-134 is extremely corrosive.
I found it while looking for an R-12 replacement for my 85 nissan truck. It works so well that I put it in the honda as well. Since it runs at such low pressures, it puts much less drag on the engine. I can "barely" tell the difference with the AC on.

However, I don't recomend doing this unless you have the right tools and know what you are doing. Refrigerants can be very dangerous.

Well, it's fixed. The part that fixed it was the thermal protector. I'll try and post their worklog later today.

Re: A/C Compressor Won't Engage
 

I owned a 2018 Honda Civic and within three months the condensor and compressor went out in the dead of a heat wave. Honda replaced both as required by their recall. Several months later the a/c goes out again this time it's the condensor. Honda tried to tell me that since debris got into the grill where the condensor is housed damaged the unit and not covered under warranty (anymore). I had to spend $2000 to replace the a/c and mitigated the grill to prevent any debris from entering and damaing the unit I just replaced. Honda didn't think they needed to pay for it. So I sold the car and now I want to warn everyone:
DO NOT BUY ANYTHING FROM HONDA. They use inferior parts for their vehicles and are not the "helpful Honda" they claim to be.

https://www.motorbiscuit.com/unhappy...oken-ac-again/

Re: A/C Compressor Won't Engage
 

You replied to an 18 year old post for a different generation Civic. Please don't do that.

So, was the condensor damaged from debris like they said? If so, they were definitely in the right to not cover a damaged condensor. You'd be hard pressed to find any manufacturer that would cover that.

You have had one bad experience. Honda's are still much more reliable than a lot of other brands.