2010 Honda Fit Sport

My AC sometimes works and sometimes doesn’t. I can get it to reset seemingly at random just by turning it on and off again via the AC dash button. I’ve been through a dozen threads looking for angles— so far I’ve checked two 7.5 amp fuses (#10 & #43), the under-hood ac relay (audibly hear and feel click when finger on the relay), and visually confirmed the compressor turns on/off and spins properly under the hood (while someone else toggles the dash button). We brought it in, and the pressure was good and the air got cold at the compressor and at the dash vents (clearly it was working properly during the testing, unfortunately), so I don’t think it’s an issue with the lines or amount of refrigerant.

Does anyone have any ideas about what in the system might be broken or further troubleshooting? Is this something maybe about the clutch or something related to the vent system that redirects air from non-ac to ac route (is that even a thing?) The bit that gets me most is that it seems to work/not work at random and can be reset by toggling the dash button — which only works like 30% of the time and at random.

thanks in advance!

 

Hello. Had the same issue on my 2010 Fit. AC went from intermittent to non-working. Next time it fails, pull over and with the car running and AC on check to see if the AC clutch is spinning. If not, then look into replacing the clutch.

 

Good call. Thanks!

The clutch spins freely by hand but is not kicking in when I press the AC button. Ack.

 

Was told by a Honda tech to replace the AC relay. I'm told the contacts develop high resistance when they get old and this can eventually burn up the clutch since it doesn't provide enough power to pull in all the way.

 

That’s a good tip, thanks! So to make sure I have this clear: the AC compressor relay could still make the audible and feel-able click (when a finger is placed on the contact) when the ac button is pressed, even if those contacts are too-high resistance?

 

Well I’ll be. I just swapped the blower fan relay with the compressor relay and, low and behold, the blower fan isn’t working but the compressor clutch is! Wild stuff. I’m 99% sure I was hearing and feeling a click from that relay, so maybe the click can still happen despite corrosion? Or maybe I’ve gone mad. Either way, thanks so much for the help!

photo attached. Bad relay top. Best I can tell that little bit of matte metal is the problem, if corrosion truly is the culprit.

 

It will still click on and off, but the contacts inside the relay go bad. If you buy a replacement, open up your old one and post a picture of the contacts. It will help others with similar issues.

 

Tried to disassemble it but it’s pretty firmly stuck (molded?) together. Any tips on how to open it?

 

Probably need to cut around the base of the housing with a Dremel or something sharp enough to cut through the plastic.

 

So after having been diagnosed with failing Compressor ,I okayed the dealer to go ahead and replace compressor . They could not remove bolts from compressor that were attached to oil pan . I had to pay for a new oil pan as well as new compressor .

 

I did some tests on several of the relays in questions. I have about 10 of them from various salvage yard trips, plus a couple that are in our daily drivers.
2010 Honda Fit, AC compressor clutch, no operational problems. 113,000 miles
Mitsuba 7001 420221
Coil resistance 157 Ohms, dropping resistor 1200 Ohms
Contact resistance .005 Ohms. you can see the contacts are kind of raggedy.



08 Civic, AC compressor clutch, no operational problems. 158,000 miles
Omron G8HL-H71
Coil resistance 146 Ohms, the 1000 Ohm dropping resistor had fallen out since the pins holding it broke. Should normally be 120 Ohms.
Contact resistance .046 Ohms. you can see the contacts are badly worn.



Random Omron Relay from my collection. You can see the contacts are shiny and rounded. This must have had very little use.


New Omron G8HL-H71 relay purchased from Amazon
Coil resistance 125 Ohms
Contact resistance .005 Ohms.

To conclude, once you get over 100,000 miles or if you replace your AC compressor, you may as well spend a little more and replace the relay too. Looks like Honda may have superseded the Omron with a Mitsuba relay (A05 version). The Mitsubas have a 1200 Ohm resistor and look to be a nicer design. They also have a higher coil resistance of around 150-ish Ohms.

 

This is awesome. Thanks for sharing!

 

Are they same equivalent relay? Looking at aftermarket one and only see blower motor one listed.