crowtoo

Hello, I am a frequent reader of this forum but I hardly ever post. Now my car has an issue and I need to tap the vast knowledge here for advice.

1) The past several weeks I have noticed that occasionally when I turn my AC off it keeps putting out cold air from the vents. On days where it has gotten warm enough that I need to use the AC for the beginning of my drive home from work, I noticed that after I turn it off the air coming from the vents is still quite cold. Colder than it should be with the AC off. I'm thinking the AC has been sticking in the on position.

2) Last Friday on the way home from work I was sitting in traffic and all of the sudden I saw what looked to be white smoke coming out from under my car in the front. I immediately pulled off the road to check it out and after raising the hood I could not find anything leaking. On the passenger side in the front, one of the plastic shields looked wet under the compressor, but nothing was currently leaking and I couldn't reach down far enough to see exactly what the fluid was. The guy who was behind me in traffic also stopped and he said it looked like I vented nitrous or something from my car. I also looked at the road where I was sitting when the "smoke" appeared and the road was dry. In addition, when I pulled my car over to take a look under the hood, the car stalled.

3) The car was barely driven over the following weekend but the next week when I was on the way home from work I had the AC running and I noticed a rough idle when I was slowing to a stop. The RPM's would drop and then come back up and then drop and come back up, in a rythmic pattern. The car stalled a couple times while sitting at stop lights. I turned the AC off and after a few miles the rough idle/stalling problem seemed to go away.

During all of these issues the engine temp was fine, so there was no overheating at all.

I've read several other threads on this forum from people with similar problems and I think I know what my issue is. I think that my AC clutch relay is stuck on causing drag on my engine as well as causing the pressure in my compressor to rise when I was sitting in traffic, and the relief valve vented the excess pressure which is what caused my "smoke" and the wet plastic shield on the passengers side. I think it's also possible that my fan relay could be bad as well and I should probably check that too.

Can anyone advise me if I am correct or add any additional thoughts?

If I need to replace the AC clutch relay, I was reading that there was a better relay than the stock one and I should replace it with the new and improved one. Does anyone know what the brand/part number of the new relay is for my vehicle?

If this is my problem, I would like to replace the relay(s) myself and I will then take it to a shop to get the relief valve replaced and the system recharged.

THANKS a million for any assistance anyone is able to give me!

Chris

ezone

You're right.


1) Clutch relay has been stuck on, so the compressor cannot shut off.
This will usually kill the battery overnight if it remains stuck on.

2) System vented excess pressure because the compressor has been stuck on without the radiator fans running. This causes extreme high side pressure and puts a large load on the engine, this is why it dies sometimes at idle.

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Needs the clutch relay.
Ask your dealer parts department for Honda part number 39794-SDA-A05, about $21 MSRP.

Original failure prone relay brand is OMRON
Updated relay brand is MITSUBA
You can read the names on top of the relays.



The AC system SHOULD have the high pressure safety relief valve replaced and it needs the lost freon and oil replenished.
Valve is part number 38801-PDF-E02, about $39 MSRP

The relief valve may no longer be trusted to vent at the correct pressure now that it has been used (per Honda service info).
The freon you lost when it vented the cloud out will make the system inefficient and cause poor cooling.

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Clutch relay is position #12 in the pic here







Fan relays are ok, unless the fans stay on after the car is shut off. Not a usual problem at all.



HTH

fcs

Would you advise replacing a functioning OMRON relay with MITSUBA as a preventative? Seems like $20 to avoid a problem like this is prudent.

ezone

IMO yes -- as long as the improved part is installed.
It's not real expensive, and you greatly reduce the chances of a significant service bill if the original relay fails and is not noticed in time.


If I had a car with one and a spare $21 in my pocket, I'd do it.