Its been a bloody long time coming has this fix (noticed the fault on March 18th this year!)but finally after changing a shed load of bits and some completely pointless expense due to poor advice, I got it fixed this past week. 
The symptoms started as the compressor not kicking in. I went to a VW specialist that I have used a lot in the past, and who fitted my clutch.
March :-
Following a check for any error codes, and a regas (£25) the advice given said that if there was a voltage to the compressor, then it was knackered (or at least the clutch on it was). Why he didn't do this simple check before the regas beats me....... anway, voltage detected with multimeter.
April :-
Brand new compressor purchased off Ebay (£192 from someone who purchased but then traded the car before fitting, rather than £1k from Seat). Compressor changed (£100). Regased (£25). Still not kicking in.
May :-
Rather than mess about, chucked it in to local Seat dealership. They ran a range of tests and concluded that there was a wiring issue. Quoted "upto 3 days labour to run through all wiring test, and then it might be the controllers" but advised not to change controllers in case dodgy wiring blew them. Gave me a quote of £68 per hour + VAT but didn't charge me the diagnostic of £55 + VAT which all credit to them (Miller and Middleton in Colchester), they didn't have to do. Anyway, decided that I would somehow fix it myself or live without it.
Tested in-car controller panel on ET-Cupra's car (very good/brave/trusting of him and big thanks still due) and it worked fine, his failed on my car so concluded not controller panel.
June :-
Bumped into an old mate from 20 years back (yes - I am that old and should know better by now) by pure chance who in a conversation of "what are you doing these days then ?" turned out to be an autoelectrician and aircon technician for a main dealer (won't mention the brand). How lucky was that ???
Anyway, we checked all the main points for voltages and all seemed OK except one strange thing...the voltage to the compressor........ a multimeter showed a 12v voltage. His test probe showed none. We did the same test on our Octavia VRS and the probe and multimeter detected the voltage. Wierd.
He took the car into work whilst I was away on my hols and he tested all the wiring and we managed to prove that it was all seemingly OK at all the main test points. He also tested the gas pressure which was good, and put some dye into the system in case there were any leaks, but detected none.
Anyway, under his advice of them not always throwing error codes if they go faulty, I swapped the pressure switch as a precaution - made no difference, but only cost a few quid so not too bothered about that. It was more important to remove the element of doubt. PITA to change it though as its right against the bulkhead and obscured by the main intake hose which was a bitch to move to create room needed to get in to change the switch.
During all of this I had noted that the rad fans were not spinning at all. We ruled out faulty fans which led back to the fan controller as the only thing we handn't proven.
July :-
Got a new fan controller (£20 ebay) and went to fit it. Now, this controller is well hidden on the underside of the metal plate that supports the battery tray so you get to it from underneath - which means splash covers off, turbo hose into FMIC off, battery tray out, etc etc and some sretching to reach the bloody thing to get the electrical connections detached.
Eventually, got the main connection off and noted some blueish corrosion crumbling away near a water hose - and spotted one of the wires to this connection had been rubbing against the metal clips on this hose and worn through completely. The fan controller is basically a pair of relays with some other gubbins in there, but it explained our wierd voltage. The probe had given enough loading on the circuit the switch the relay in this controller to a dead link, hence no voltage (well that's our theory!!). The multimeter by design does not not place any real load on the circuit so the relay does not switch and therefore shows the 12v.
FAULT FOUND!!!!!!! Waheeeey!!! Autoelectrician mate popped round and soldered in a fresh piece of wire to link it all back up, connected back in, popped the battery back on, started car and compressor finally kicked in!!!!
So, put it all back together, refitted all the guards, removed jack and axle stands, cable tied loom back from any metal clips, started car and .................... no cold air.
Mate took car into work and regassed. Found that it had 0.4Kg of R134a instead of .75Kg. Topped it up and hey presto........COLD AIR after just over 4 months of messing about, I have aircon just in time for the weather to turn sour!!!![[B)]](/forums/styles/seatcupra/oldforumsmileys/shades.gif "Cool [B)]")
I love the Leon again now.
The rubbing wiring was a result of the loom being detached from a supporting bracket that would hold it away from the water hose. The clips that would hold it in place were all still there and once reattached they were very secure. I cable tied it up too as a precaution. We'd never have spotted this without being under the car changing that controller as its all very much hidden behind all the hoses etc.
I suspect that the VW "specialist" that did my clutch in February had unclipped this wiring to get the loom out of the way, and then didn't clip it back up. Although the clutch fitting was only a £50 "drink", it then cost me £392 in parts, gas and fitting + £50 "drink" and £10 case of Stella to my autoelectrician mate to put right shoddy work. Guess I won't be going back.
Big Thanks however to my old mate though who didn't charge me anything like the amount his time was worth and who didn't even want the beer or cash drink I gave him.
I have also proven "old" compressor is absolutely fine and in full working order, as is the original pressure switch, and the new fan controller was never fitted. Some parts to Ebay now then to claw some of that cash back!!
The symptoms started as the compressor not kicking in. I went to a VW specialist that I have used a lot in the past, and who fitted my clutch.
March :-
Following a check for any error codes, and a regas (£25) the advice given said that if there was a voltage to the compressor, then it was knackered (or at least the clutch on it was). Why he didn't do this simple check before the regas beats me....... anway, voltage detected with multimeter.
April :-
Brand new compressor purchased off Ebay (£192 from someone who purchased but then traded the car before fitting, rather than £1k from Seat). Compressor changed (£100). Regased (£25). Still not kicking in.
May :-
Rather than mess about, chucked it in to local Seat dealership. They ran a range of tests and concluded that there was a wiring issue. Quoted "upto 3 days labour to run through all wiring test, and then it might be the controllers" but advised not to change controllers in case dodgy wiring blew them. Gave me a quote of £68 per hour + VAT but didn't charge me the diagnostic of £55 + VAT which all credit to them (Miller and Middleton in Colchester), they didn't have to do. Anyway, decided that I would somehow fix it myself or live without it.
Tested in-car controller panel on ET-Cupra's car (very good/brave/trusting of him and big thanks still due) and it worked fine, his failed on my car so concluded not controller panel.
June :-
Bumped into an old mate from 20 years back (yes - I am that old and should know better by now) by pure chance who in a conversation of "what are you doing these days then ?" turned out to be an autoelectrician and aircon technician for a main dealer (won't mention the brand). How lucky was that ???
Anyway, we checked all the main points for voltages and all seemed OK except one strange thing...the voltage to the compressor........ a multimeter showed a 12v voltage. His test probe showed none. We did the same test on our Octavia VRS and the probe and multimeter detected the voltage. Wierd.
He took the car into work whilst I was away on my hols and he tested all the wiring and we managed to prove that it was all seemingly OK at all the main test points. He also tested the gas pressure which was good, and put some dye into the system in case there were any leaks, but detected none.
Anyway, under his advice of them not always throwing error codes if they go faulty, I swapped the pressure switch as a precaution - made no difference, but only cost a few quid so not too bothered about that. It was more important to remove the element of doubt. PITA to change it though as its right against the bulkhead and obscured by the main intake hose which was a bitch to move to create room needed to get in to change the switch.
During all of this I had noted that the rad fans were not spinning at all. We ruled out faulty fans which led back to the fan controller as the only thing we handn't proven.
July :-
Got a new fan controller (£20 ebay) and went to fit it. Now, this controller is well hidden on the underside of the metal plate that supports the battery tray so you get to it from underneath - which means splash covers off, turbo hose into FMIC off, battery tray out, etc etc and some sretching to reach the bloody thing to get the electrical connections detached.
Eventually, got the main connection off and noted some blueish corrosion crumbling away near a water hose - and spotted one of the wires to this connection had been rubbing against the metal clips on this hose and worn through completely. The fan controller is basically a pair of relays with some other gubbins in there, but it explained our wierd voltage. The probe had given enough loading on the circuit the switch the relay in this controller to a dead link, hence no voltage (well that's our theory!!). The multimeter by design does not not place any real load on the circuit so the relay does not switch and therefore shows the 12v.
FAULT FOUND!!!!!!! Waheeeey!!! Autoelectrician mate popped round and soldered in a fresh piece of wire to link it all back up, connected back in, popped the battery back on, started car and compressor finally kicked in!!!!
So, put it all back together, refitted all the guards, removed jack and axle stands, cable tied loom back from any metal clips, started car and .................... no cold air.
Mate took car into work and regassed. Found that it had 0.4Kg of R134a instead of .75Kg. Topped it up and hey presto........COLD AIR after just over 4 months of messing about, I have aircon just in time for the weather to turn sour!!!
I love the Leon again now.
The rubbing wiring was a result of the loom being detached from a supporting bracket that would hold it away from the water hose. The clips that would hold it in place were all still there and once reattached they were very secure. I cable tied it up too as a precaution. We'd never have spotted this without being under the car changing that controller as its all very much hidden behind all the hoses etc.
I suspect that the VW "specialist" that did my clutch in February had unclipped this wiring to get the loom out of the way, and then didn't clip it back up. Although the clutch fitting was only a £50 "drink", it then cost me £392 in parts, gas and fitting + £50 "drink" and £10 case of Stella to my autoelectrician mate to put right shoddy work. Guess I won't be going back.
Big Thanks however to my old mate though who didn't charge me anything like the amount his time was worth and who didn't even want the beer or cash drink I gave him.
I have also proven "old" compressor is absolutely fine and in full working order, as is the original pressure switch, and the new fan controller was never fitted. Some parts to Ebay now then to claw some of that cash back!!
