3.8L Commy A/C not working. Halp.

[TC.Barky]

Hey all,

Friend of mine has a 3.8L commodore (1994) and the A/C doesn't work. Checked the fuses under the steering column and they look visually ok and I've swapped the relay under the bonnet for the A/C compressor with no joy. Apparently it's never worked while she's had it but she hates driving it in the summer (fair enough really ).

When turning it on (digital climate control), no rev changes and no click of compressor starting up. Belt/pulley is spinning but the compressor doesn't turn at all.

Don't want to go through and do a big job on it, but is there anything else that can be checked easily to at least find the fault? Is there an easy way to check if it's got enough gas? (I'm assuming it won't engage or anything if the gas level is low??)

[my.paj]

It wont run if not enough gas, a good re gas place (some radiator shops) will/should check for free and let you know what needs to be done.
Rick

[hobbo]

Most older Commys suffer from leaks in the A/C system, regas is a waste of money, you need to find the leak first then be prepared to hand over lots of cash, new Compressor or Evaporator under the dash could cost a lot. $500 - $1,000 job?

[TC.Barky]

Most older Commys suffer from leaks in the A/C system, regas is a waste of money, you need to find the leak first then be prepared to hand over lots of cash, new Compressor or Evaporator under the dash could cost a lot. $500 - $1,000 job?

Is there an easy (safe) way to check for the home mechanic? Can you put UV stuff in the system and check for it with a black light?

[Pauly Faulkner]

yeah but you need to be able to inject it in to begin with and it's a lot harder without the compressor running.

The commies are a menace when they have climate control, it's all run via the bcm module under/behind the steering wheel and those things are notorious for playing up. Bit like putting all your eggs in one basket really by having a 'one unit does all', when one function is lost you need to replace the whole unit

[m1s3ry]

You can put 12v straight onto the compressor by bridging the single wire off the compressor onto the battery with a bit of wire. At least you'll know if it actually works, then work backwards from there.

[hobbo]

Commy A/C

You can put 12v straight onto the compressor by bridging the single wire off the compressor onto the battery with a bit of wire. At least you'll know if it actually works, then work backwards from there.

I wouldn't do that, no gas means there is no lubricating oil for the rotory compressor, if the compressor is good, it wont be for long. The only way is pay for a professional leak check with the dye, then they will say where the leak is and how much to fix. If the car is great in other areas and she wants to keep it for a long time then it might be worth it but if its not dont waste the money, save up and buy another vehicle with good A/C with service history. I have seen good people with not a lot of money spend thousands on a car only to take it to the wreckers and get nothing for it. Sorry for the lecture dude.

[scruffy]

I wouldn't do that, no gas means there is no lubricating oil for the rotory compressor, if the compressor is good, it wont be for long. The only way is pay for a professional leak check with the dye, then they will say where the leak is and how much to fix. If the car is great in other areas and she wants to keep it for a long time then it might be worth it but if its not dont waste the money, save up and buy another vehicle with good A/C with service history. I have seen good people with not a lot of money spend thousands on a car only to take it to the wreckers and get nothing for it. Sorry for the lecture dude.

Quite safe to hotwire the compressor WITHOUT the motor running to see if the compressor clutch engages. Ign on, air con on, fan on, motor off, hotwire a/c compressor and if clutch engages then safe to say that the system is out of gas or an electrical fault, eg fuses, faulty a/c witch or fan switch. Bob