I have a 2008 Honda Accord with the 4 cylinder motor. It has 216,000 miles on it. Only work done on the engine other than routine maintenance has been an alternator and battery change. Recently I have noticed that my air conditioning isnt performing well. It will blow fine. Normally it will start out cold. However after some time which ranges from 30 minutes to an hour and a half, it will start blowing hot air. Since it is cold to start and it blows fine I am thinking it is either low on freon or the relay is going bad. Any thoughts or suggestions to check would be greatly appreciated. Thanks!

 

I think AC work should be left to the pros , the AC system parts are designed to work together , even the amount , type and pressure of the freon . You need the knowledge and equipment to set them up and get it working correctly . I remember one jack *** at auto zoo with a can of freon , I told him it'll probably leak right back out because that's why there's none in the system now . He didn't care about ozone , air quality or using his brains , with so many people adamantly bugging out about the environment I don't know why they even sell a can of freon to a mickey mouse mechanic .

 

Thanks for your comments. I do agree that there is a point that AC work should be completed by pros. However, there are other areas where it can be done by a fairly experienced backyard mechanic (I have 29 years of experience doing mechanic work on my cars). So I was just trying to get help troubleshooting to see if I could handle this as I really think it may be a relay issue. The relay gets hot and stops working. Thanks!

 

There is a chance that the field coil is failing on the compressor, its a fairly common issue on the V6 honda engines, not sure on the 4 cylinders, I had mine fail on my 05 TL recently. When it quits blowing cold air, does the compressor still cycle on & off? If it isn't, you can try swapping relays, there should be at least on additional one in your under hood fuse box that you could swap out to see or just buy a new one, they are cheap. Another test it to use a multi meter and see if the ohms of the field coil come up infinite or not (check it with the car off & when the a/c isn't working), I am not sure what the spec range is on your car, but when they fail and then get hot, they typically show an infinite resistance when you check the ohms at the plug for the field coil (typically near the compressor itself).

Another easy test is with the car off, hot & the a/c not working (go for a drive till it stops), remove the relay from the fuse box that controls the field coil and put power to it via jumping the pins in the fuse box where the relay sits, if the field coil is working properly you should hear an audible click coming from the compressor. If you don't hear it clicking there is a good chance the field coil is failing, which you can either replace that part or replace the entire compressor, there is also a chance that with the mileage on the car that the clutch air gap is out of spec.

You may have to do some googling to find some of the info specific to your car for testing what I mentioned, I unfortunately don't have any documents specific to your car.

If it passes all of the things I mentioned above, I would just find a good A/C specialist shop and let them see what they can figure out.