8th Generation Honda Civic Forum banner

A/C Problems? Free Things You Can Try Yourself !!! Now with diagnostic PDF!!!

18057 Views 4 Replies 5 Participants Last post by  Hardscrabble
Ok guys Ive seen people ask this a lot recently and with summer coming up i know more people will be asking about this. So first off DO NOT ADD REFRIGERANT/FREON!!! First make sure your system is actually running, really first reset the computer for your A/C system. Yes it actually has its own computer that senses if your system is running ok if it detects a problem it will turn off the compressor to avoid damage. Its very simple to do:
Clearing DTC (Diagnostic Trouble Code) for HVAC

Ignition off.
Turn fan speed off.
Turn max air on.
Press and hold the recirculation control and rear window defogger buttons and turn ignition to on.
The ventilation button will light for a couple of seconds and then turn off.
HVAC DTC's are now cleared.

I got that info from this link reply #7 =>http://www.8thcivic.com/forums/mech...al-chat/471337-c-warm-air-mystery-solved.html

I did the reset and have not had any problems since.

Another helpful link How to Troubleshoot the Heating/Air Conditioning (With A/C: Without Climate Control)

This is another free thing you can also try:
If the fans are turning on then the car "thinks" it's turning the compressor on.

For everyone who is having problems with the compressor randomly turning on / off, you need to do this test when it's acting up:

The following info i got from this link reply #9 I id not come up with any of the following info credit of info and pics gos to volvo9 8th Generation Honda Civic Forum - View Profile: volvo9


With your a/c acting up...
Open your fuse box and pull the A/C relay. We will be working on the left 2 terminals in the relay socket. The relay is just an electronic switch that connects these terminals. You can start your test by tapping this gently with a screwdriver end... if it turns your ac on (car on for this test) then the relay is your problem. If not, turn off the car, pull the relay and proceed.

With your multimeter on the voltage setting and the negative probe grounded (battery terminal is fine) Check voltage at the left most terminal in the socket. You should have battery voltage here. If not, check the fuse.

Change your multimeter over to Ohms and stick a probe into the center terminal, (only the vertical ones, don't touch the horizontal ones on the right) and leave the other probe grounded. This checks resistance of the clutch coil... here you can see mine is reading 4 ohms... good. You want a reading around this number, nothing vastly higher, or nothing next to 0. An infinite reading (the same result you get with test leads not connected to anything) is a broken clutch coil, or an "open circuit"... A really low reading (0, or .3 or something) is a clutch shorted to ground that will keep popping fuses.

If your car passed the above 2 tests next you want to jumper the 2 terminals together. This should give you a thunk / click as the ac clutch coil engages the compressor clutch. You can use a paperclip for this, but here I put my multimeter on Amperage and completed the circuit with my multimeter so I could measure current draw to show the people who will test it. You can see my coil is pulling 3.4A of current (about 45 watts). This step is optional and just helps prove everything is correct... be careful because not all multimeters support amperage testing and some cheaper ones only do 2A or less.

If you click on the PDF file below it will give you tons of info on our A/C system


See less See more
1 - 5 of 5 Posts
awesome post, i'm gonna try to tackle an AC job this is a great thread i'm surprised there isn't more activity on it.
Good info, thanks!
I used some of those posts by "volvo9" to diagnose an A/C problem with my daughter's EX. Very helpful.
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.