AirCon

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camel_landy

Original Poster:

5,084 posts

190 months

Wednesday 31st July
quotequote all
Hi All,

So I've not got any AC at the moment and I suspect the AC clutch isn't engaging. The little blue light comes on but that's about it.

Anyone got any tips?

...the location of the fuse will be a good start as there isn't anything listed. hehe

M

camel_landy

Original Poster:

5,084 posts

190 months

Wednesday 31st July
quotequote all
So it appears to share the same fuse as "Heating & Ventilation System" (Fuse 17), which makes sense.

Without the engine running, I can hear the relay behind the dash 'click'... Good so far.

Annoyingly, the rest will probably have to wait as I'm not at home and I don't have a volt meter with me.

M

notaping

343 posts

78 months

Wednesday 31st July
quotequote all
A few things to check - with the engine off, check you can spin the compressor by hand - just try to turn the plate on the outside of the pulley. If it's been sitting for a while with no gas in it then the bearings could have rusted (I stripped my system at the start of summer and my compressor was seized).



Then to check the clutch - disconnect the red wire at the compressor and connect it to +12v. Just momentarily connect a wire to the battery. The clutch should click in.

If all that works - then the compressor and clutch should be ok.

Next is the dryer. That sits in front of the passenger front wheel - behind the large rectangular panel. There's an electrical connection at the top which is basically a cut off switch. If there's too much moisture in the system it cuts power to the compressor. Because of it's location the terminals on the connector can get pretty cruddy and stop power getting to the compressor. If the system hasn't been running for a while, or no gas in the system then take this opportunity to replace the dryer.

Those are the first things I would look at.

G.

camel_landy

Original Poster:

5,084 posts

190 months

Wednesday 31st July
quotequote all
Awesome... Thanks for the details.

I swung by Screwfix earlier and grabbed a multimeter. I'm not getting anything at the clutch, when the system is on but 12v direct to the clutch makes it engage.

The dryer tip is very useful as I've given a local aircon guy a shout, so he's coming to have a look tomorrow.

Cheers,

M

notaping

343 posts

78 months

Wednesday 31st July
quotequote all
Hopefully he'll be able to sort it out for you. It was the dryer switch connections that stopped the power on mine. The air con guy should have a replacement dryer with him - I think they're fairly common. If not, I got mine here . . .

https://shop.airconcoparts.co.uk/epages/es117975.s...

£25 ish.

notaping

343 posts

78 months

Wednesday 31st July
quotequote all
Oh - to get to the dryer you need to take the front wheel off. Just to make life easy!

camel_landy

Original Poster:

5,084 posts

190 months

Wednesday 31st July
quotequote all
I'm hoping the system now just needs a topup... I gave the clutch a 12v 'kick', while the engine was running and it now all appears to function correctly, with the clutch engaging and disengaging on the button. smile

M


camel_landy

Original Poster:

5,084 posts

190 months

Thursday 1st August
quotequote all
So the system is mostly running fine now... I say 'Mostly'.
  • The system was basically empty.
  • Vacuum Test - Passed
  • Filled with refrigerant.
  • Ran up the system and it's blowing much colder than before.
However... When we shut off the engine, we could hear a slight 'hissing' from the area around the compressor. Urgh. The hissing stopped after a couple of minutes but even though the chap had added dye to the system, we couldn't see anything. confused

We've left it for now. I'll run it as a suck-it-and-see and if needed we'll get it properly looked at later this month when it goes in for a 12k service.

M

notaping

343 posts

78 months

Thursday 1st August
quotequote all
That's good. If it held vacuum then it shouldn't be leaking, but for peace of mind you could spray some water with a touch of fairy liquid in it over the couplings where you hear the hissing. Bubbles will appear very quickly if there's a leak.

Do you have any idea of the amount of refrigerant the chap used to fill the system? Just for future reference.

alabbasi

2,697 posts

94 months

Thursday 1st August
quotequote all
There's a pressure switch that prevents the a/c from engaging if there's not enough freon. Put some gauges on it to see if you're low. If you are, find and fix the leak first,

camel_landy

Original Poster:

5,084 posts

190 months

Thursday 1st August
quotequote all
notaping said:
That's good. If it held vacuum then it shouldn't be leaking, but for peace of mind you could spray some water with a touch of fairy liquid in it over the couplings where you hear the hissing. Bubbles will appear very quickly if there's a leak.

Do you have any idea of the amount of refrigerant the chap used to fill the system? Just for future reference.
That's what we thought... Holding vacuum = good, which is why we went ahead and filled the system.

...but that's also precisely why he adds a dye to his fills, as it will fluoresce under UV light. When we looked, there was no trace, which we found odd.

As for how much refrigerant - 950g. Before he turned up, he was trying to get some data on the car but no-one knew. He ended up turning to the forums, where there was talk of between 900g - 1000g, so he plumped for 950g.

M


camel_landy

Original Poster:

5,084 posts

190 months

Thursday 1st August
quotequote all
alabbasi said:
There's a pressure switch that prevents the a/c from engaging if there's not enough freon. Put some gauges on it to see if you're low. If you are, find and fix the leak first,
Given the history of the car, I'd not really paid much attention to the AC and given it sits around for a couple of months at a time, it didn't surprise me it had lost pressure... However, that's why we performed a successful vacuum test before doing anything else.

Now it's a case of monitoring and seeing if we do indeed lose pressure. If so, the next steps are probably swapping out the 'o' rings on the joints.

M

alabbasi

2,697 posts

94 months

Friday 2nd August
quotequote all
camel_landy said:
Given the history of the car, I'd not really paid much attention to the AC and given it sits around for a couple of months at a time, it didn't surprise me it had lost pressure... However, that's why we performed a successful vacuum test before doing anything else.

Now it's a case of monitoring and seeing if we do indeed lose pressure. If so, the next steps are probably swapping out the 'o' rings on the joints.

M
When a car sits, the a/c can lose pressure because the seals dry up from oil not circulating through the system so it's better to run the a/c all the time. Re-gassing seems to be a common thing in the UK and not in the US. I suspect that it's because people turn the a/c off in the winter or to save on fuel. In that case, it's a false economy.

Byker28i

67,983 posts

224 months

Friday 2nd August
quotequote all
I've chased so many leaks in mine, had it running great for a couple of years until I had the engine out, then they didn't refill the gas.

No gas/low gas means the compressor won't run - as previously mentioned.

It seems I now have had a pipe to the condensor chafing, which means rad out etc, and probably a new condensor as it's original and the pipe seems welded to the condensor through the two different metals and age. Urgh.

Even when it's working on the early cars it was never great. Worked on on a warm british summer but never good in hot weather/on the continent. I've just got used to having the windows open.

notaping

343 posts

78 months

Friday 2nd August
quotequote all
Byker28i said:
. . . I've just got used to having the windows open.
Same.

My goal this spring was to get the A/C back up and running. All was going great 'til I had a massive blowout from the front - engulfing the car in gas (I had about 750g in the system). I suspect the condenser, but since that's rad out - it's not happening 'til winter. Something to look forward too. frown

camel_landy

Original Poster:

5,084 posts

190 months

Friday 2nd August
quotequote all
alabbasi said:
When a car sits, the a/c can lose pressure because the seals dry up from oil not circulating through the system so it's better to run the a/c all the time. Re-gassing seems to be a common thing in the UK and not in the US. I suspect that it's because people turn the a/c off in the winter or to save on fuel. In that case, it's a false economy.
Oh yes... Very aware of all that.

It's a common misconception in the UK that you only run the AC when it's hot outside. People don't understand that AC will dry the air and significantly improve de-misting performance in winter.

M

camel_landy

Original Poster:

5,084 posts

190 months

Friday 2nd August
quotequote all
notaping said:
Byker28i said:
. . . I've just got used to having the windows open.
Same.

My goal this spring was to get the A/C back up and running. All was going great 'til I had a massive blowout from the front - engulfing the car in gas (I had about 750g in the system). I suspect the condenser, but since that's rad out - it's not happening 'til winter. Something to look forward too. frown
Same here for both.

As I'm just about to head off to France & Spain, I figured I'd have a quick crack at it before I go.

I've sorta resigned myself to stewing in my own brine during the day and jumping in the hotel pool on arrival at the overnight destination!! hehe

M