on1chikun

So I have been having some issues with my A/C the last two years.

Two years ago, the blower motor went out on a longish drive (~4 hours). I ordered a replacement online, replaced it, and viola! The A/C worked for another two years.

The other day the same thing happened on a 5 hour drive. I immediately went to Honda service dept, and picked up a certified Honda component. Changed it. And viola it.... still has a problem!

The A/C works perfectly for about 2 hours, and then around the 2 hour mark, the blower motor slowly stops blowing. If I turn the AC off for awhile (~30 minutes) the blower motor works again, for about 1-2 hours. Even when the air stops coming out, however, I can hear what sounds like air being forced through a crack, which is what made me think of a damper issue.

I am also thinking there is either a damper problem or there is a power transistor on the A/C controller board that is overheating for some reason. I am not too savvy on the details of the A/C in this car -- is there an official document somewhere?

Thanks for any input.

ezone

Let me ask:


You say it "slowly stops blowing".
I want to know, when this happens, if the fan is still running but there is little or no airflow?
Airflow slowed way down but the blower still sounds like it's running full speed?

When you stop and let the car sit long enough to get the AC working again..... There is a HUGE puddle of water now under the car?

I assume this is a yes.


The evaporator core froze into a big ice cube.
Because.....
The compressor isn't cycling off when it should to regulate minimum temperature.
That leads to 2 main possible causes:

1) The evap temp sensor or control unit has a problem related to sensing the core temp and allows the evaporator to get below freezing temperature. (Not real common IMO.)

2) (Much more common) The clutch relay is stuck on, causing the compressor to run continuously..... and probably will drain the battery overnight. Does that happen?

CLUE: Start the engine, leave the AC and everything turned off. Is the compressor clutch engaged and causing the compressor to run when it shouldn't?


Tap on the clutch relay. Does the clutch let go? Replace the relay with the improved part.
Updated relay brand is MITSUBA
Updated Honda part number is 39794-SDA-A05

You must ask for this part number at your Honda dealership, most parts people seem to just look up the original relay and don't know about the updated part.
An original part will eventually have the same issue later on.



AC clutch relay is in position #5 in the underhood fusebox.



Oh yeah, this relay sticking problem can be intermittent and random. It might work just fine at times, then stick on and cause problems. It can go back to normal with just a slight bump and work again for a while. Might be difficult to catch it in the act, but should be easy to figure out if you do catch it while stuck on.


HTH

speedy25

Hey ezone! Nice to see you are still dispensing good info to us that cant find it.

Finally getting around to tracking down an AC problem in an '06. Compressor stays on all the time. I looked for the relay and was about to post a pic to find out which one it really is and found you already did it. Thanks for pointing out #5. I'll check that out and see its really the problem.

edit: Just CAREFULLY read your post above and saw the note about the updated relay. Why the heck does Honda seem to hide updated parts from customers! I ruined two sets of tires before I found your post about the rear control arm update. Arrggh!

I recharged the system tonight and after running a while the low side rubber hose was covered in condensation. I never saw that happen before. Anything to worry about?

-SP

ezone

I try. Sometimes.

I gotta watch it though. There may be spies.
Someone else the other day said theirs was caused by the control head, and I hadn't seen that in an 8th gen yet.

You must not be looking in the right places! Warranty could have covered the tires and the updated arms if you got it to the dealer
A) Within the warranty period, and
B) After they came up with a resolution to the problem. (it took a while for them to come up with a fix), and
C) With the correct complaint

Letters were sent to registered owners about the recent warranty extension (now expired).

Are you the registered owner? Is your information current with Honda (corporate)?
Dealers don't update customer info with the manufacturer, apparently that's your responsibility. (like new owner of a used car)

Ever leave a glass of icewater setting out? What happens to the sides of the glass?


Sweating (water condensing) on cold surfaces is normal.

HTH

speedy25

Yeah I know condensing is normal, I just never saw it on an AC hose before. Heat transfer through rubber usually isnt much since its mostly "insulation."

More silliness-

Now that I know which relay, I pulled it. Exceptionally warm! As expected compressor stopped its work, but both fans stayed on. I made sure that the AC was shut off at the controls and turned the blower fan on and off just in case it needed a cycling. I would have expected the fans to stop when the relay was pulled.

New relay ordered. Should arrive on Monday.

Control arm foo-foo- Its my sweeties car. She bought it new in fall '05. No change of address happened since then either. Honda would have had the right info. Did that extended warranty cover ruined tires? I did find out about the class action suit, and since the terms were very poor, opted out of it.

-SP

ezone

Any relay that is continuously turned on will be warm due to the electromagnet coil inside..
A STUCK relay would not be warm because the contacts are just stuck closed, electromagnet is not energized.

Maybe the coolant temp was high enough to need the fans to run?

If the HVAC control head (even though it appeared to be turned off) was still providing the AC rquest signal to the PCM- the fans and clutch would be on as long as the PCM will allow it.

Maybe someone threw the letter away. That seems to happen a lot.
IDK what you opted out of ($1.62 cash?), but you should have gotten the updated arms while you could.

The only bulletins I could find are the newer versions, not the original versions so I'm relying on crappy memory here.

Under the 3/36 warranty, yes I think the tires were covered a little-- with pro-rating, measuring remaining tread depth, etc..


Under the extension, tire issues not handled in the shop. That discussion and decision was made elsewhere (instructions and contact info were in the letter I believe). We only replaced the arms and did the alignment under the extension.

speedy25

#5 was much warmer than the other relays, but then it could have been because the others werent energized. I have handled relays that were stuck before and they were never as hot as this one. I wish it wasnt potted so I could pop the cover off and check it out.

Coolant temp wasnt an issue. The car had been sitting a while.

Your idea that the controller is still sending a request signal is what I think it is too, but dread the thought of trying to find out why and fixing it. Is there a separate controller "ECU" for the AC? or is it all contained on the push buttons below the radio?

I'll have to hook up a scanner and see just what relevant info I can get about whats happening on AC control.

-SP

ezone

HVAC-->MICU-->BCAN-->CAN-->FCAN-->PCM


If I thought it was the issue...
I'd try unplugging the HVAC panel and see if the compressor shuts off then.
(I haven't had to figure this out yet, someone here reported the HVAC panel was their problem some time back)