breakerfall

Hi all. I'm new here.

I've got an AC problem with my wife's 09 sedan. For a week or two now, the air from AC is more not cool than it is cool. Sometimes it will come on cool and then un-cool after about 15 mins. After that, it will not be cool again until the car is turned off and back on (and then often still not cool).

So, I got a can of AC recharge today. Going through the motions, I started the car and put on Max AC (no cool air). As soon as I connected the kit, the pressure gauge on the filler was pinned to high. At this point I couldn't determine if the compressor was running over the engine and fan noise (I've since learned that it probably wasn't on). Since the pressure was pegged at high, I did as instructed and didn't try to put in any of the recharge freon.

Did some googling and found some people talking about the low pressure switch going bad. Found some instructions on an HVAC self test involving the dashboard button cluster. No codes flashed. Coincidentally after I did the test, I started the car and had cool air from the AC. Since I knew the compressor was running now, I rushed to do the recharge. Recharge, recharge, recharge. Pressure in the green. As the can was getting empty, though, the pressure was decreasing slowly. Finally the compressor turned off along with the fans for a few seconds, and the pressure pinned to high. Then the fans started back up, pressure stayed high, and the cool air that had been blowing from the vents was now just outside air temp or a bit warmer.

Tried the HVAC test trick again. No codes. No cool air this time.

So I've got a definitely full AC system where the engine fans run when the AC is on (per the dash lights) but the compressor seems to only run when it feels like it.

That's my story. Any ideas?

Thanks!

ezone

Turn the AC on.
Wait for it to quit cooling.

Get out, open the hood.
Tap on the clutch relay (or maybe beat on the fusebox).
If it starts running again, you need a new relay for the comp. clutch.

breakerfall

Went and got a new relay yesterday since it was like $5. Installed and started car with Max AC. Cool air. Cool. Good for 5-10 mins. Compressor "cycled" like it did on Sunday before the cooling stopped, but this time the cooling continued. Cool. Turn car off, feeling good.

About an hour later, I go to pick up some food (Greek, if anyone's wondering) and air is cool the whole way there. Car off, grab food. Car on, cool air. Drive. 5 mins later stop at a light. Cool air changes to outside "vent" air. Not cool.

Ideas?

ezone

$5????? For $5 I'd expect it was not a dealer part. For $5 from a dealer I might expect a fuse.


Which relay did you replace?

(Engine compartment fuse and relay box, Left half of the pic) The relay in position #5 is the clutch relay. The other relay labeled with a snowflake is for the condenser fan motor.

The new and improved relay is about $30. The original design is much cheaper.
Updated relay brand is MITSUBA
Updated Honda part number is 39794-SDA-A05

breakerfall

I replaced #5. I've seen mentions of the updated part, but figured that for troubleshooting purposes I could get away with the cheaper one. The replacement I got from Advance is labeled exactly the same as the one I pulled (OMRON brand, other markings also identical).

Thanks for continuing to help me out with this...

ezone

What exactly happened here?

Did the HVAC controls change from recirculate to fresh air on their own?

Did you check if the compressor was running or not?

breakerfall

No change in HVAC controls. Lights still indicated max cool.
Couldn't check compressor as I was stopped at a light in the middle of the street. How can I tell if the compressor is actually running? I mean, I can see when the engine fans are running but the compressor pulley is always spinning whether on or off, right?

Thanks again.

ezone

the belt is always spinning the pulley, yes.

You have to watch the compressor clutch hub to see if it is spinning. THAT'S what you look for.





I know this is a Ford, but this makes it easy to tell, having 3 big pucks and all..... The Honda clutch hub isn't quite so obvious.

rglacues

Hello all, I'm new here as well and have the same issue: AC blowing cold air for a good 5 mins and slowly warm air, vent air. I checked under the hood and the clutch isn't engaged. I've checked the clutch relay and even switched it with a good one, no clutch didn't engage.

Any help in diagnosing and any other suggestions would be greatly appreciated.

ezone

Hi there, welcome.

What year is your car?

What is your temperature gauge doing when the AC quits? (Is the radiator full?) The PCM will cancel AC operation if the engine is overheating.


Got a test light or voltmeter? Test if the clutch coil is still getting power when the clutch stops engaging.