Air con not working, any ideas

[tony209]

bought my C70 T5 with a non working aircon. It's not been working for the 3 years I've had the car and previous owner said it had stopped working the previous year so approximately 4 years in total. I've decided that I want it working so took it to Halfords (big mistake!) They had an offer and they claim to do a system check prior to regassing. All they did was check that the system could hold pressure for a bout 2 minutes then recharged the system. So I have a fully charged system but the ac still doesn't work. There's no activity at the pump when the system is switched on, I tried a direct power connection from the battery to the positive terminal on the pump and the clutch activates. I've checked the ac fuse and changed the relay but still nothing when the ac is switched on - any ideas on what to check?

[4x4]

Could be anything from overcharged to undercharged to a faulty pressure switch


My air-con compressor wasn't working on my 850 when I recently bought the car. I took it to a local garage that I have used before for air-con recharges and they re-gassed the system after checking for leaks. The compressor still didn't kick in and they investigated further and found a broken wire to the compressor

[tony209]

Originally Posted by 4x4

Could be anything from overcharged to undercharged to a faulty pressure switch


My air-con compressor wasn't working on my 850 when I recently bought the car. I took it to a local garage that I have used before for air-con recharges and they re-gassed the system after checking for leaks. The compressor still didn't kick in and they investigated further and found a broken wire to the compressor

I'm thinking along the lines of a broken wire to the compressor. I've checked VIDA but that was no help, just says "a/c system off"

[V70Zig]

In Vida you should be able to check the a/c pressure, I think it's in Diagnostics then Vehicle communication...double click on ECM...hit the + and scroll down to a/c pressure and click on that......you should the see what pressure the ECM is seeing.......
If it's 0 then unless you know it's fully gassed and has no leaks, it will more than likely the pressure sensor.

As you have Vida go for a drive with it connected up showing the a/c pressure and see what readings it gives.....Mine went from 0 to loads and kept fluctuating.........new pressure sensor fitted...sorted.

[Clogs]

If the compressor gap (at the pulley end) is too large, it won't click in despite the system being gassed. You'll need a feeler gauge to see what will go in between the magnetic clutch plates. See Youtube video. I used 3 short copper
wires from single strand electrical cable to slide into the springs on the clutch plate instead of plastic cable ties, as they can be flattened a bit if the gap is too small and needed to be a bit wider. Result - cold air. Re doing the shims is really fiddly and will require regassing. This job was a bit fiddly but about an hour to give it a try.

If it doesn't work, you've only wasted an hour!


https://www.youtube.com/watch?v=zOjqjR8Mz64

[tony209]

-176kPa stationary and doesn't change while driving.

Clutch gap is tight at 0..6mm, 0.5mm slips in more easily

[Derek UK]

With everything running and the AC switched on, use a broomstick to push against the compressor clutch. If things are wrong it shouldn't be rotating. If it clicks in under pressure the gap is too big. It might click off after a few seconds. The measurement should be taken in three places to confirm the gap. 0.5mm good, 0.6mm bad. If you can get an 0.6mm in all 3 positions it likely needs reducing. Because they are so thin it is difficult to force them in so if they go in at all they can be considered to fit. Lots of videos on the tube about this. Go to Robert DIY.

[850Red]

In my 850 I replaced the evaporator, drier, condenser, pressure switch, and regassed it many many times, before realising that the orifice tube was blocked. A £2 fix, after all that.

[diplomat2.6]

Originally Posted by 850Red

In my 850 I replaced the evaporator, drier, condenser, pressure switch, and regassed it many many times, before realising that the orifice tube was blocked. A £2 fix, after all that.

My orrifice tube was also blocked too. My guess is that it is an attempted cure for a leaking evaporator. I renewed everything, and I smelled a terrible burning smell after several weeks of it working brilliantly. It then never worked again.
I'm not really sure whether to explore, or cut my losses! However, I suspect a clutch issue too, even though it was a brand new compressor.

[V70Zig]

Originally Posted by tony209

-176kPa stationary and doesn't change while driving.

Is that a minus ?

Just read mine with engine off 5min after a 30 mile drive home -
9030 hPa which equals 903 kPa. I think last Saturday morning after being stood overnight it was 3990 hPa (399 kPh).

If the ECM is receiving a low reading it won't allow the compressor to kick in. How low is the minimum I don't know, but if that is a minus then there lies the problem.

Could still be a wiring issue, but to the sensor or a duff sensor.

If you really want to get it working then check if there are any mobile a/c engineers in your area as they are the experts (allegedly)....a bit like Main Dealers ha ha...............someone like this - https://chesterfieldcarairconditioning.co.uk/