How to fix air-conditioning in 2008 Honda CRV

Question

I have a 2008 CRV and recently the air conditioning stopped working I have already tried replacing the relay thinking that might’ve been it when I turn the air-conditioning on I can hear something kick in and the idle of the car goes down so it seems like the air-conditioning compressor is turning on however the air coming out of the van never gets cold.

Unfortunately the car has over 100,000 miles on it and I know that there have been recalls on the air-conditioning compressors.

As a next step what can I do to try and diagnose the problem I was thinking perhaps I would try adding refrigerant but it seems strange to me that the air conditioning would just stop working all the sudden if refrigerant where the issue.

Is there any harm in getting a can of refrigerant and a hose and trying it out other than the fact that I’ll be spending around 30 or $40?

Answer 1

In the States, a can of R134a refrigerant can be had for about $5. There's a problem with what you want to do, though ... putting more refrigerant into the system if it doesn't need it will cause it to become over pressurized and will start blowing seals and/or other parts of the AC system. You'll end up spending even more money in repairs.

Without specialized tools/equipment, there are some things you can check. If the AC compressor is working, you should be able to see (and hear) it turn on. The clutch will engage and the compressor itself will start turning. This is a very easy thing to recognize. If working properly, the compressor will kick on/off at regular intervals.

If it is turning over, the next thing to look at is to see if the AC lines are getting cold. Right after the compressor turns on, put your hand on the refrigerant lines. It should be noticeable very quickly where they are getting cold or not (one will should get cold, while the other should get warm).

If the compressor is not turning over, then you need to have the r134a levels checked in the system. This can be done by weight or pressure. In either case it takes special tools to measure this.

As you alluded to, the CR-V's are known for "black death" which kills the compressor, and creates havoc for the rest of the AC system. I'm not sure which years this affected, but it was a huge issue and a true PITB to get fixed.

Answer 2

First of all check if your compressor hasn't seized yet. Very simple. Engine off and keys in pocket, reach for the compressor's clutch hub (the flat part in front of the pulley) in the engine bay and turn it with your hands for some turns. You should feel smooth and uniform resistance across one whole turn. If not, the compressor's bad.

If the compressor's good, then turn AC (or defroster) on and visually check for clutch hub rotation. If it's stationary, then you might either be too low on refrigerant or the clutch assembly might be defective.

If the clutch doesn't engage with AC on, locate the compressor's power terminals and, with a multimeter, check for voltage coming to the terminals from the engine harness. With AC turned on and engine on, you should get 13-14 volts if the ECM/low pressure switch is powering the compressor on (which means enough refrigerant to allow compressor operation).

The compressor, being of the scroll type, should have a thermal switch on the body and this may make checking for clutch coil resistance (a good clutch coil should have a resistance between 3 and 6 Ohm) difficult if the thermal switch has failed (as with any part subject to wear, they can fail and cease conductivity).

If the compressor clutch is actually engaging with AC on and engine on, then you should be looking at how, and most importantly how frequently it cycles, in addition to touching the lines and feeling for their temperature. And only then you may look at a charge issue (which you shouldn't ever solve with the canned refrigerant: go have the system serviced by a licensed professional equipped with a recovery station).

2008 sounds too late to come equipped with the Keihin compressor (the one giving trouble). You more than likely have the Sanden one.