Z3 Air Con not working

[Jjim]

On my newest Z3 the Air Con doesn’t turn on. When I press the button, it lights up.... but nothing happens. The fan doesn’t engage.

I’ve checked the fuses and they are all fine.

Any suggestions on where to start looking?

 

[t-tony]

The system has a pressure sensor, if there's no pressurised gas present it wont supply a live to energise the Electro-magnetic clutch on the compressor. You can try supplying a live feed to the wire at the compressor and see if the clutch "pulls in". If you're lucky a simple re-gas may be all you need mate.

Tony.

 

[Jjim]

Thanks Tony, will look into a re-gas first

 

[t-tony]

Someone who is honest will tell you if it's worthwhile before they waste any gas Jim. They should do a vacuum test before injecting gas. You can buy a re-charge canister off eBay but that will only pressurise the system regardless of any leaks. It could be a cheaper way of testing for leaks, but where I worked we had a bottle of CO2 (pub gas) which we used to test for system leaks.

Tony.

 

[handsomejackuk]

you could short the pressure switch just to confirm the clutch engages and actually runs the compressor but dont run it for very long as the compressor needs oil which is in the gas i think.... i did this just to confirm mine needed regassing but i have never bothered as dont think i will ever use air con anyway...

the pressure switch is behind the driver side headlamp mounted on the drier canistor...

 

[guyglemieux]

My son noticed that my compressor has no strap. He believes that it may not work. He thinks that I might need a new compressor and strap. He also thought that there might other bugs. I guess I had better give up the ship before I sped a couple of thousand dollars. If the car runs don't fix it.
What is your opinion? I don't have that kind of money.Wise choice?

 

[t-tony]

By strap?, you mean drive belt? If so it's not necessarily a deal breaker. There could be other reasons a belt has been removed which could be expensive to put right. You can run a car without A/C anyway, do you need it to work?

Tony.

 

[guyglemieux]

I should have said the belt, sorry. We think it was taken off on purpose to put less strain on the HP. I don't really need it. It would be nice. I'm a Sund ay driver. I could live without it. I've bought a recharge kit which contains 2 refills and an anti stop leak. I will use it on my Jeep. When we do a refill, do we have to remove whatever is left in the system or should I presume that it is empty?

 

[t-tony]

Hard to answer that one. Where I used to work before I retired we used a bottle of CO2 with a pressure regulator to pressurise the system to check for leaks. That way you don't pollute the atmosphere or waste expensive AC gas.
When refilling an AC system it should be "vacuumed" out to remove on air and moisture in the system before re filling with AC gas. One word of warning is that the gas has a very low boiling point and if you get it on your skin it will boil causing very nasty burns, so if you're not sure have a trained person do it.

Tony.

 

[Nodzed]

Jim the condenser for the AC is very venerable being at the front of the lower rad and are easily holed, ask me how I know! Chances are this is the case, both my z3s had this issue, defo as said get it tested, mobile guys will come and put a luminous dye in and check it out.

 

[Zephyr]

Reviving an old thread.
my AC engages, starts, brings cold air to the cabin and then the compressor stops/starts/stops/starts probably forever.
should it stay constantly on? Now it pumps for about half a minute and stops and instantly starts.
no errors- my tool reads also active-inactive-active-inactive so this pattern is verified.
any input? Should I be worried?
(M43TU19 in case this matters)

 

[t-tony]

I would be inclined to suspect 2 things. 1, wiring to the electro-magnetic compressor drive and 2, the system as pressure switch.

Tony.

 

[Zephyr]

The wiring looks solid, well connected and not crispy. At least from what I can see with my eyes and flexible camera.
should I try a refill maybe? And see how this goes?

 

[Zephyr]

Pressure switch, you mean this Tony?

 

[t-tony]

Is that the one screwed into the side of the condenser? I changed it on my Z3 but to be fair it stopped altogether. When it detects low pressure in the system it cuts power to the wire (1) to the compressor drive. I'm not sure what else would make it keep cutting in and out as you describe.

Tony.

 

[Zephyr]

Yes. It is that.
So we come to a sort of conclusion that it is a pressure issue.
I will try to refill it with that coloured stuff and check for leaks, then replace that sensor and if nothing happens regret spending and take it to a shop to get it fixed. thanks once again Tony.

 

[Nodzed]

AC compressors do not run continously, once turned on and down to temp they become a demand system clicking in and out as required.