I have a 2010 Honda Fit. The A/C is intermittent - runs fine for about 20 minutes, then no cold air for about 30 minutes, then sometimes starts cooling again. Not consistent; sometimes doesn’t work at start but then begins to cool after a while. Shop said (April 2) that Freon 134a pressures were OK. I noted that a few times I checked the Freon lines from/to the compressor, and when it works the low pressure line is cold; when it didn’t the lines were outside air temperatures (not hot, but both about the same). Anybody seen this phenomenon before? Taking it back to the shop Friday, my spouse complains when it doesn’t work. rjs
Intermittent cooling is often caused by the components of your vehicle’s AC system freezing up. Typically an iced over evaporator is the culprit. An evaporator covered in ice can’t cool the air, so you would have to wait until the ice melts, which is why the cold air eventually returns. There may be numerous issues causing the icing—from a dirty cabin air filter to a blocked evaporator drain or an overcharged system. Look for puddles of water under your car—this could be a sign of a freezing problem.
If the system was freezing up, would not the line back to the compressor be cool/cold? Recall the lines are warm when it stops working; low pressure line cool when it works. Yes I believe fans are running; former car I had would overheat when radiatir fan stopped working.
Cabin air filter was changed in April when I took the car in. Puddle of water is insufficient; good systems also produce puddles, my experience. What else can I look for?
What else to look for ? The description of the repair on the invoice of the shop you are taking it to on Friday.
We had a similar problem with our 2003 Toyota 4Runner. It turned out to be a defective relay that controlled the compressor clutch. The fact that sometimes the air conditioning doesn’t come on when the car is first started and then comes on by itself later rules out the evaporator freezing up.
I had a Ford Aerostar where the air conditioning would stop cooling after a while. The shop.sttached the gauges and when the cooling stopped, the pressures went sky high. It turned out that the radiator fan clutch was slipping so that insufficient air was being drawn through the condenser. The technician brought his shop fan over and aimed it through the grill. The pressures dropped and the system began cooling.
Thank you, THAT is a useful reply!
I still am searching the local library for a Chilton’s or similar manual for the 2010 Fit; the diagrams tell me where to find those relays. That happened on my 1984 Chrysler Laser; fan relay burnt out multiple times got used to replacing it. Finding it was the first step. At least the intermittent nature tells me the fuse hasn’t blown (yet!).
That’s one indication that the expansion valve is malfunctioning.