aircon compressor not cutting in

[brucewaller]

Folks,
Having worked well since a new condensor was installed 3 years ago, the GQ aircon has stopped working. Fan OK, Switch and Relay OK, there is power to plug at receiver dryer and there appears to be power to the single wire plug at the compressor though this voltage is confusing as it comes up as only 0.15 on the multi meter (am earthing the meter on the block which may be the problem considering my lack of electrical know how). Nothing obviously out of order at compressor that I can see.

Any ideas out there? I searched the site and found reference to the temperature regulator near the glove box?? Am about to go and have a look for that.

Cheers all,

Bruce

[Bigrig]

Hang tight mate - one of the more electrically minded will be along to assist no doubt ...

[MudRunnerTD]

Behind the right side head light is the aircon dryer canister. Mounted to the top of it is a pressure switch for the aircon. Take the 2 wires off and bridge them for a second. If your AC compressor fires up your out of gas.

[brucewaller]

Thanks MudRunner. Tried it and no joy, compressor doesn't want to come to the party.

[Rip'n'Shred]

You could try a jumper cable direct to the compressor from the battery positive. If the clutch locks in you know the clutch is ok. Don't need the engine running for this.

I would guess the clutch is ok. You should get a solid 12v the way you tested it.

Low gas is usually the problem but. Is there power on both sides of the plug at the receiver dryer?

[brucewaller]

Rip and Shred, I will go and check these things out. May take a while, will need to think of some new words to say as I try and pull that plug off the compressor again.

regards,
Bruce

[brucewaller]

Rip and Shred,
Jumping the compressor from the + terminal has indeed got a result out of the compressor.

[brucewaller]

There was also power on both sides of the plug. Green/red terminal 12v with Fan and A/C ON, Green/Yellow terminal 12v with fan ON and A/C switch OFF - nothing there with A/C switch ON. Excuse the terminology but colours make it easy for me.

Regards,

Bruce

[brucewaller]

That's the receiver/dryer plug I checked for the power at both terminals.

Bruce

[BigMav]

mate how many wires have you got coming out of your filter drier? do you have a small electric fan on the front of the condensor? (the radiator looking thing in front of the actual radiator) Can you take a pic of the plugs you are testing at and post it up. Your description is a bit confusing but it sounds to me like you are getting power to the switch but nothing after it? One even easier way to check if there is pressure in the system is to take one of the caps off the service valves and depress the valve inside just quickly and see if anything is in there.

[Yendor]

There was also power on both sides of the plug. Green/red terminal 12v with Fan and A/C ON, Green/Yellow terminal 12v with fan ON and A/C switch OFF - nothing there with A/C switch ON. Excuse the terminology but colours make it easy for me.

Regards,

Bruce

So with the fan and A/C on you have 12volts on the Green/red terminal and 0volts on the Green/yellow terminal?

This means that the pressure switch is open.

Try bridging the two wires together again as MudRunner suggested, you will need to have the fan and A/C on.

[Rip'n'Shred]

As above ^^^ x2

The easiest way is to take it to an air conditioner mob and ask the check the gas pressure, unless someone you know had the manifold and guages.

I would put my money on gas leaked out. Usually leaves a oily black wet stain where it leaked from.

[brucewaller]

Olgeta, bridged the wires again and no joy from the compressor, the relay switching on and off can be heard but nothing from the compressor. Took the charging cap off and there is pressure in the system, whether it is where it should be I cannot tell without the proper equipment. However when I bridged the compressor from the positive terminal yesterday the compressor kicked in and out as required.
I may be mssing something here but will bite the bullet and cart her over to the experts.

Thanks for the help.

Bruce

[brucewaller]

BigMav,
No fan at the condensor. Just the one plug with the 2 wires at the receiver/dryer. See my latest post for the bridging results and the pressue check. I agree that there seems to be power to the Receiver dryer but nothing beyond. That would explain why when I jump the compressor direct from the battery she kicks in and out but no joy via the electrical system after the receiver/dryer. Thanks for the help.

Bruce

[Yendor]

OK, remove the relay, with ignition off you should have power in one of the terminals the relay pushes into, do you?

If yes, then try swapping the relay with another one the same colour, does the A/C work now? if not try bypassing the pressure switch again.

If there is no power check your main fusible links near the battery for a blown one or a possible bad connection.

[brucewaller]

Thanks Yendor, prior to going through your suggested steps I gave the aircon switch another go and lo and behold the compressor kicked in! I wonder if all the pulling and replacing of plugs, cleaning of contacts and liberal use of RP7 has had a positive effect. Cool air is once again flowing. I won't get too cocky though, it's only a matter of time.

Bruce

[dion_83]

I have a similar problem with mine so I decided i'd hotwire the clutch with the engine running, air con on, all gased up and still no cold air, these days none of the elec system for the air con works not even the switch so next time I'm feeling energetic the whole lot is coming out.