Thanks. I've now confirmed that the electrical part of the equation is working. I've tested the wire going to the compressor and it is energized as it should be when the compressor is not kicking in. So it would appear that it is the clutch that is not activating. Again, it works when I start the car up after it has been sitting for an extended period, but once it cycles off while driving, it will not re-engage. It was very hot out when this first started, but today it was mid-70s this morning and the system exhibited the same pattern.

Jeff, to your note, I was under the impression that replacing the coil and clutch (that's one assembly, right? ) was quite difficult to do without removing the compressor. Is that not correct? [I just looked at a schematic and it looks like the coil and clutch are separate units.]

I've not had a shop suggest replacing the unit. That was my thought that IF the compressor needs to be removed, why not just replace it at the same time. But if the clutch / coil can be replaced without removing the compressor, that would change the equation considerably.

Further question: I understand that there is a AC cutoff pressure switch. Am I correct in assuming that if that were the problem, the wire to the compressor would not be energized? (that is, it cuts off the compressor by cutting off the current to the clutch).

 

Replacing the clutch and the coil does require removal of the compressor, and special tools. The reason I suggested it, short of a new OEM compressor assembly with everything included, the remanf. or aftermarket units are usually junk.

The pressure switch cuts power to the clutch under high pressure situations. So if you have the A/C on and power to the compressor coil, then no, the switch is not your issue. What happens is the air-gap between the clutch and hub gets to big, so when it heats up the clearance increases and the coil is no longer strong enough to engage the clutch -OR- the clutch has an intermittent OPEN condition when it gets hot.

 

That makes sense and fits the symptoms. I get the point about the compressors. I was looking at this site that shows a new Denco unit with the clutch (but I now realize perhaps without the coil) for $216 or $242 depending on my specific VIN number.

03 2003 Honda Accord A/C Compressor - Climate Control - Action Crash, Delphi, Denso, Four Seasons, GPD, Metrix, Spectra Premium, UAC, Valeo - PartsGeek

Now a question about the circumstances of this. See my original post, but this problem cropped up shortly after my alternator failed and was replaced (along with a new belt). I can't really see how the two could be connected, but after 13 years of no problems, it does seem odd that these two units sitting right next to one another would fail within a week of one another. Clearly they didn't break a wire, since the AC works some of the time. Is there anything related to the serpentine belt that might result in the AC symptoms? Perhaps with a new belt there's more tension? It's just a strange coincidence.

Thanks

Tom

 

Chalk it up to a strange coincidence.

Those units you are looking at have the clutch and coil installed on them, and not a bad price for everything. OEM parts will cost you more, but it's up to you.

My coil failed at 165k miles...over 205k now, no issues, original compressor, blows 45 degrees at the vent.

 

Thanks to Jeff and PA for great help and input on this. I think we've nailed down the issue. I'll take it by the shop I use and get their thoughts.

Jeff, just for the record, are you saying the Denco compressor I linked to while made by the same company may not be to exactly the same specs as OEM?

Also what would be a reasonable labor price to replace the coil and clutch?

 

The Denso is an OEM compressor, but it may be manufactured under license by another company now...hard to say.

I wouldn't even guess at price, parts prices and labor times are all over the place these days.

Good luck, and let us know how it turns out.

 

Only diy'rs generally replace a clutch coil or remove a shim from clutch plate. AC/Auto shops don't want the responsibility for a repair that may fail later, and besides they get the markup on much more expensive compressor replacement. It's a no-brainer from their POV.

Expect to get quotes for AC compressor replacement. Cost will likely push towards $1K for parts and labor.

You can find videos on youtube describing clutch coil replacement or clutch shim removal. It's a pretty challenging job to accomplish w/o discharging the system.

good luck

 

If they have to remove the compressor and discharge the a/c, the repair will be expensive.

If the coil is replaced without discharging the a/c, then cost will go down.

Here is a video talking about this type of repair.

 

Thanks everyone for your input on this. Given the location, the clutch cannot be replaced without removing the compressor. The shop I use (and where I've had generally good experiences) told me that some shops will just replace the clutch, but they do not if the compressor has to come out. They've had complications in the past and decided for them it wasn't worth it. A new compressor with the clutch assembly really wasn't much more than just a clutch, so I had them just do it. He noted that I could get the same Denso compressor online that he would by getting for less and he'd be happy to install it for me. I opted to get it through them as 1) we're in the midst of record heat in DC so the idea of waiting another week wasn't appealing, and 2) they'd be on the hook for any problems. They got it done the next day and everything works great.

Thanks again for the help. In the process, I learned a lot about how these clutches work.

Cheers

Tom