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updated air-con compressor relay to prevent failure

AC/Heater 
392K views 643 replies 222 participants last post by  culzean 
#1 · (Edited)
This is a common cause of failure of the A/C on our civics.

In fact just a week ago Honda issued a Bulletin about it. The original fit Omron relay is suseptable to moisture ingress. This can form nitric acid in the presence of the normal arcing as the contacts operate. This will lead to corrosion and eventual failure. The Bulletin warns that the relay can fail either open or short circuit. If the latter this forces the compressor on to 100% duty cycle and can burn it out.
The remedy is a replacement relay from a different manufacturer - Mitsuba - that is a better quality item. The bulletin warns that the EPC is not yet updated, so you have to order this countermeasure part number directly to recieve the new part, otherwise you will just get the "old" part. I'm surprised they are not doing a campain over this considering if can fail in a way that might lead to screwing up other parts of your aircon

This the bulletin number:-

SM-10-002-00

It affects ALL civics (and CR-V and jazz) upto and including 2011 model year

Here is the countermeasure part number:-

39794-SDA-A05

RELAY ASSY., POWER (MICRO ISO) (MITSUBA)



The datasheet for the original Omron part is here:






The specific part is G8HL-H71 which appears to be a Honda specific version not listed on Omron's website - the standard relay is 180ohm and the Honda version is 120ohm coil resistance.​


The Mitsuba part seems to already be used on other Hondas. I found this link for example​


 
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#3 ·
Does it mean that if I have failed relay, Honda change it for their cost regardless if my guarantee finished or not?
As far as I am aware normal warranty applies. So if your car is out of warranty to will have to pay for the part. However its worth asking for goodwill, especially as its a known problem.

Regardless of this, you can easily fit it yourself so no labour involved and the part is around £25 so not a big deal at the end of the day.
 
#7 ·
What part to order ?

There you go:


It's already the new Omron relay.
I have a problem with my A/C it just doesnt trigger the compressor when i turn A/C on.. could it be the relay ? What part should i order ? the G8HL-H71 ? Can i test the relay in any way?

Thanks
 
#11 · (Edited)
This relay failed on my car @ a year ago. It flattened the battery completely so the car was immobile. I think this also led to early failure of the battery

Thanks for this very useful thread as I can check if the improved part is fitted

Some people may want to change out the relay to avoid a possible future breakdown
 
#15 ·
Today, 23:28 * #3 (permalink)
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I have the type s 2.2 cdti 2007 aircon intermittent after regas replaced omron relay with newer mitsuba one higher resistance and now works a treat sold on eBay or supplied by your local dealer. Hope this helps because I've looked for a month to find answer on forum.
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#16 ·
Many thanks for this post. I thought I'd reach at least 12months without something ELSE going wrong but it wasn't to be :rolleyes:

My AC stopped working on the way home today. I took the offending OMRON relay out and I could hear something rattling inside. I gave it a quick tap and refitted it. The AC started working again. I went straight to my local Honda dealer and they sold me the uprated relay for £21. All seems to be fine now.
 
#18 · (Edited)
Interesting thread......
A couple of months ago i found that my air con was not blowing cold anymore, so i had the system checked and re-gassed by a local specialist and all was fine.
Due to the weather after that i wasnt using cold air very much, but it was warm the other week and my car was roasting, so was very annoyed to find that i had no cold air at all. :(
I went back to the same company, but when they checked it they said it had not lost any pressure. The guy looked under my bumper to where you can look through to see the condenser, and showed me that there was some damage to it(could have been caused by stones hitting it), which he reckoned could be my problem.
I done some checking and found that a new condenser including fitting would be in the region of £250 - £300, so i decided this was not worth paying and resigned myself to never having refrigerated air in my Civic again.

After reading this thread i sat in my car and noticed that i could not hear the compressor coming on as i turned on the air con. I checked the fusebox and i have the original Omron relay.
I am hoping that the updated Mitsuba relay will cure my problem, so i have ordered it from ebay using the above link.
I have nothing to lose by trying it, and will be delighted if it does the trick.
In the meantime i have the old relay here in front of me(extremely tight to remove - had to use pliers), so can confirm to the person who asked earlier, yes the car runs without it and everything works exactly the same.....apart from the air con compressor of course. ;)
When i get the new relay i will post here and let you know if it made any difference.

Oh, whenever i buy anything on ebay, i always look to see what else the same seller has, so i ended up buying this at the same time. :D
GENUINE HONDA 2012 BTCC TOURING CAR TSHIRT BLACK/RED WITH ALL SPONSORS LOGOS | eBay
 
#21 · (Edited)
#22 ·
Well i received the relay today and have just fitted it, but unfortunately it made no difference, and my compressor is still not coming on. :(
It was definitely worth a try though.
As i said before, there is visible damage to my condenser, so i think its virtually guaranteed that my particular problem will cost in the hundreds to fix properly.
Weighing up the cost against the relative infrequency that i use the air con(at least for refrigerated air), together with how much longer i am likely to keep the car.....then it is just not worth getting it fixed.

I am actually quite disappointed with Honda, because i dont think major parts of the air con system should be failing at just over 4 years old.
My previous car was a 5 year old Ford Focus, then before that a 4 year old Volvo S40, both of which had perfectly functioning air con that had never required any maintenance at time of trade in.

On a happier note, the BTCC shirt that i ordered from the same seller is excellent. :D
 
#23 ·
Hmmm sounds like a similar problem I have, changed my relay with no luck. Cannot hear the compressor coming on. Maybe give it to a local garage to inspect it or see if there is any fault codes.

Also disappointed with Honda, as my previous car a 2003 bmw, had perfect cold working aircon.
 
#29 · (Edited)
The only thing that makes it 'approved' is Hondas own part number. The unit hasn't been made by them, they just brand it as their own to make it hard to source 'non-Honda' replacement parts for a quarter of their price.

EDIT:- I've just ordered one and a pack of micro fuses, as delivery is free over £6.
 
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