I have a 2002 Honda Accord EX 4 Cyl. The other day, when driving on the freeway, I noticed that when I turn on the A/C, only room temperature air blows out. Since air does come out, I don't think it is the blower under the glove box. I looked under the hood and noticed that with the A/C on, A/C fan and Radiator fan both turn on, but then off very quickly (~3 seconds). The car hasn't overheated after driving distance. When I turn on the A/C, I have not seen the compressor clutch engage at all.

I'm not that experienced with troubleshooting these kinds of things, but have been doing a lot of searching on the Internet, so I've tried a few things:

1. I double-checked all controls on dash to make sure they work (fresh air/recycle button, A/C on/off, made sure temp is on coldest)

2. I checked all fuses (under hood, and next to driver/passenger side doors and they look fine)

3. I've switched the 2 fan relays in the fuse box to see if one was broken. This made no effect on the situation, so I switched them back.

Is there anything else that I can try? I would really like to at least figure out what is wrong and possibly fix it before going to the mechanic.

Thanks for any help,
Andrew

 

The system might be low. If you have a volt meter you can test the AC pressure switch to see if there is continuity across the pins - the switch will "open" (no continuity) when the pressure is below ~28psi or above ~455psi. This is to protect the ac compressor from damage.

 

Thanks Poorman. I do have a voltmeter but admit I don't really know how to use it! I will figure it out and report back.

 

OK, I found the pressure switch and tested it with my multimeter. There was no continuity between pins. I also tried to "jump" it with a paperclip, then turned on the AC and watched the compressor clutch engage and the AC/Radiator fans turn on.

So, I'm guessing that this means my system is low? Do I need to add refrigerant? If so, is this something I can do myself or should I take to the mechanic?

Thanks again for your help.

 

If the system's low, I'd just wait til the spring to re-charge it.

 

mclasser, why wait? Is it because a little is always going to constantly leak out of the system?

 

If the system has gotten so low it won't kick on the AC then there is a good chance there is a leak somewhere.

There are some DIY kits you can get that will allow you to add refrig to the system. Be sure to read and follow the directions. So you can add some now and see how long it holds. If it does not hold the charge for very long then some AC repair is going to be needed.

 

Got it. When you add refrigerant to the system, do you have to completely remove the old? Otherwise, how do you know how much is still left in the lines?

 

I'll be straight up, the answer depends on the person.

Some will say that you should have the system emptied. Pull a vac on it, be sure it holds that vac for 20~25 minutes. If it does not hold then find repair the leak. Then re-charge the system by weight (add the proper oil and amount if things were replaced) and test both the high and low pressures to be sure they are within spec. Depending on the pressure readings - more to it as there are things that influence those - either you are good to go or more repairs might be needed.

Some/many will get the DIY kits from the parts stores and add refrig using just the gauge - that comes with the kit - on the low side and call it a day.

So you can get a "kit" for $20~$30 and put a charge in the system and see how long it holds....again, if it doesn't hold for very long.....plan on a trip to an AC shop in early spring for an AC repair ($200 to $1,500 ? depending on what they find).

If you are in North America, do you need AC this time of the year? Not really, most it might help with is to defrost the windshield in certain conditions.

It is up to you on what to do.

My youngest son (22) drives a 97 and it has an AC leak - I know where it is. For the last 1 1/2 years I haven't repaired the leak yet.......too lazy and getting the car to stay still long enough for me to do it have prevented the repair to date. So I go through a can or two (12 oz) in a years time. It never gets as cold as it would if I fixed the leak but it will cool enough on the really hot days and allow him to defrost the windshield in those "humid conditions".

 

I am having similar problems with my accord 98. the compressor doesn't engage when the AC is switch on, I was told to replace the compressor for effective coolness