chipster1977

My A/C seems to be working 80% of the time the car is running, even though the fan control **** is OFF, and the AC button is not green. Sometimes after driving for over an hour vapour starts coming out of the cabin vents above the radio and then the AC basically starts losing its cooling power and then the fan speed gradually slows to nothing??

Does anyone know what this could be? I am thinking its a bad relay.

ezone

Clutch relay stuck ON.



Open the hood.
Observe the compressor clutch.
Is the compressor running (clutch engaged) when it shouldn't be?

Find the relay that controls the clutch.
Tap on it.
If the clutch disengages, you need a new relay.

Post your answer back here. Honda has an updated relay for this problem.

chipster1977

I turned the car on with the fan **** off and the ac off. I could hear the compressor on immediately, I tapped the AC relay and nothing happened, then I pulled the relay and it stopped. I put it back in and the compressor didn't turn on again.

ezone

Put a clutch relay in it.
Sounds like the contacts were welded together and it couldn't turn off.
The original relays have this issue, it is one of a couple common problems it has.

The updated relay info:
The improved relay is MITSUBA brand, not omron.
Honda part number 39794-SDA-A05.
Just call your dealer and ask if they have this part number in stock.
MSRP is $25.25

Don't bother telling them what car it is for, or they may try to sell you an original unit. It will have the problem again eventually.

Or you can buy it from this place. It is a little cheaper, but you pay shipping too.
http://www.hondaautomotiveparts.com/...VIN+Number+---



Oh yeah, for anyone reading this
Clutch relay is: top row, second from the left in this pic



HTH

gearbox

iTrader: (95)

wish these relays werent so expensive or i would replace it. i dont know why they cost more than $5. mitsuba is far superior to omron btw, not sure what honda was thinking with that one.

ezone

IMO, 25 for a relay is cheap compared to repeated AC problems and a tow truck call for a dead battery.

FYI the omron relay 39794-S0K-A01 is $6.62 USD MSRP

gearbox

iTrader: (95)

i just meant in general. quality automotive relays are normally not that expensive. bosch/tyco for example are around $5 or less and last near forever.

im not a big fan of replacing parts tho unless they break.

Matt_75

I was looking at this link ezone, the more expensive piece 17 I believe:

http://www.hondaautomotiveparts.com/...ENGINE+ROOM%29

It says that the part is a MATSUSHITA but it lists it as part number 39794-S04-004/014 for $22.52. I looked up a 2005 4dr lx as well and it gave the same part number except no 004 at the end of the part number. Is this wrong or an updated part number beyond what information you provided? Or am I looking at the wrong relay?

ezone

The part number I gave you is an updated part, as per the service info (copy below).

Look for the article titled "A/C Problems or a Dead Battery? Check the Compressor Clutch Relay", last page of the article. It gives the same part number I already gave you:
http://dvpatel.homelinux.com/forumfiles/SN/A110900.PDF

Service info for a specific issue trumps catalog info, in most cases.


HTH

Matt_75

Cool beans. Thanks for info.

Would you consider this a preventive maintenance type deal where even if I'm not exhibiting any of these symptoms, you'd recommend it be changed anyway?

ezone

How do you figure that?

From what I gathered in the first few posts, your relay was stuck on.

That is the specific issue the service info addresses.

Therefore,
you need the updated relay to avoid having this reoccur.

So no, this isn't preventive. This is a (supposedly permanent) fix.

(If you had zero symptoms and a perfectly working AC system, and I said replace that relay, that would be preventive maintenance.)




I realize that the evap freeze-up you had wasn't listed as a symptom, but it is still caused by the bad (stuck) relay..
There are several different things a user MAY or MAY NOT notice when the clutch relay goes bad. It doesn't matter if you did or didn't notice any of the symptoms listed, the cause of the problem was the same. Therefore, the fix needs to be the same.




Or you can plug in another $7 omron relay and maybe have the problem pop up again in the near future. You may or may not notice different symptoms then, too.


HTH

Matt_75

Ummm....I'm not the OP. It was chipster1977. This is Matt_75.

I know. We all look the same right.

I was just looking for general info and your opinion on whether or not to replace it for preventive maintenance. My car does not exhibit any of these symptoms so I'll take your preventive maintenance portion of your post as a "yes, spend the $25 to keep you're A/C from crapping out or killing the battery."

ezone

BAHAHAHA....

**FACEPALM**

Damn, I didn't EVEN look at who posted what.
Durrr. Sorry.

Yeah, you can if you want.
I can't even say that 100% of the original relays ever fail.
At work, it is generally frowned on to "upsell" something like this before there is a problem that is related to it.
I've seen plenty though.

Seems like about half of them that I see get replaced for a dead battery complaints. Only some of those have actually burped freon out of the relief valve. The other half are actual AC complaints related to the relay.

Matt_75

No worries. I figured that's what happened. We always appreciate your help.

I'll probably pick one up tomorrow. I called the dealership at closing time and they said they had 2 in stock. Of course, it's Hawaii, so it must have cost them an arm and a leg to ship it. It's $32.38 plus tax.

IMO very small amount to pay for peace of mind.

Thanks again for the info