Aircon compressor test

[OxfordChris]

Hi,

Some of you may have seen my recent question regarding the failure of aircon on my 51 Cupra 20VT http://www.seatcupra.net/forums/showthread.php?t=119007. I’ve not actually managed to solve the problem but I’ve ruled a few things out thanks to steering provided by the group.

I just wanted to try something else out before handing it over to the Seat dealer ($$), I was thinking of connecting the compressor clutch directly to the battery to see if it engaged (the evidence I have seen so far points to a poor connection from the fan control unit / poor earth or a broken fan control unit).

I was hoping someone out there with a better idea of car electrics/mechanics could tell me if this a really stupid thing to do or should it just engage the compressor and make the aircon work (disengage when I remove the current)?

Cheers,

Chris

 

[techie]

Nope its a fine thing to do and something we have to do on a new compressor to set the clutch up.

12v and an earth and you should hear it click in.

 

[OxfordChris]

Hi techie,

Thanks for that. So its just +ve and -ve terminals of the battery to the connectors on the compressor (making doubly sure I get the right polarity of cause). And when I disconnect the clutch should disengage should it (just checking)?

Shame you are not a bit closer to us, i'd be more than happy to pay for a few hours of your time to sort this out ... never mind.

 

[techie]

If you disconnect the connector on the top on the compressor it doesnt really matter which was around you connect it it will just reverse the effect.

Powering it up will engage the clutch the same as it would if you turned the a/c on.

 

[shiggsy]

Hi folks - im having the same problem on my 1.6S (not climate controll). Air con is not coming on at all, although the button light does come on. Cannot hear the compressor clunk into action at all.

I want to do a bit of diagnostic myself first if possible before booking it in to be looked at. I got myself under the car today and found the compressor, but the only connections I could see were a green/brown pair on the underside. Is this 'where you have been getting the 9v reading, across these two?

Have yet to check the fuse (i know, should have been the first thing to check!), but I read that it is shared with the heater - which is working fine - so im guessing its not going to be that

any help or diagnostic advice would be really appreciated

 

[Fl@pper]

dont forget that if there isnt enough pressure in the system the clutch wont engage anyway no matter wether the light is on or not

 

[shiggsy]

yes, thanks - i am wondering whether pressue is the issue. don't suppose you know where the pressure switch is - I could have a go at bridging that momentarily to fool it.

Also, any ideas what sort of current the compressor draws? Ive got a 12Ah lead acid battery somewhere I could use to connect directly the compressor to see if i can get it to engage - but im worried whether im looking at the right connection or not since people seem to be talking about the connection being on top, but im looking at one on the bottom