Technical Air Con pressure switch

[8585]

Does anyone know where the air con pressure switch is located on the MK2 punto? It's a JTD if that makes any difference?

I've had a look but cant spot it anywhere obvious. It is the switch that prevents the compressor engaging if the air con gas pressure is too high or too low.

Cheers

 

[a1ant]

Hi mate,

If you remove the drivers side wheel, and the the drivers side inner wheel arch liner, if you look behind the front bumper, you will see a silver cylinder. The pressure switch is located on the top of this.

Checks the pins for corrosion FIRST before replacing if your having trouble with it.

Hope that helps,
Alan

 

[8585]

Cheers Alan, I've got it! The pins appear to be all fine though.

Basically, the AC isnt working. It has no leaks and has just been regassed to the correct pressureetc, so after a bit of research and electrical diagnostics, I think it is the pressure switch at fault.



Does anyone have a haynes manual with the AC wiring diagram in it? If so, a picture of the diagram would be massively helpful!! I left my manual at work 50 miles away, and have the car apart on my drive now!

Cheers guys

 

[a1ant]

Hi mate,

bare with me a sec and ill see if i can work out how to get the wiring diagram on here. Its not from haynes though.

Have you checked the connection on the underside of the air-con compressor? It controls the clutch, allowing the air con compressor to engage. If you look up from under the car at the bottom of the air-con compressor, you will see the two wires just to the left of the aux drive belt pulley.

Alan

 

[a1ant]

Hello again,

This is the wiring diagram for the air-compressor engagement circuit...

Hope that helps,
Alan

 

[8585]

Yes Alan, I have checked that connector too. The compressor engages fine if i apply 12v onto that 2 pin connector, so the compressor is working. The actual swith in the car is working fine too (and the led illuminates)

I've done a continuity check on all 5 pins on the pressure switch and none of them have continuity, (which i thought to be a bit strange) I just dont know what wires do what on the pressure switch. When i know what the wires do, i can short a few out to confirm it is the pressure switch.

Thanks for your help Alan, it is much appreciated

Craig

 

[8585]

Your a legend! I'll try and work ouit what is wht on that diagram now

Thanks a lot for that mate

 

[a1ant]

No problem mate,

K120 is the pressure switch

Alan

 

[8585]

Still really confused here, my pressure switch has got 5 wires but K120 is only showing 3


From what I have described baove, does it sound like the pressure switch is at fault? I cant think what else could be causing the issues, unless the remap I had done recently could have trashed my ECU like it did my clutch!? Had the remap took off again tho, so back to stock now.

 

[gtaboyz]

Alan

Seems your the man in the know, I've got a jtd punto, had it regassed today and I was told the aircon gas was fine however, there was a electrical fault, I took the car and tried the aircon, worked fine for the 5 miles home, went out later that night, pressed my aircon button, orange light came on, but no cold air?? Looked under compressor and wire looks tight, but unable to check, why would it work then stop working, where do I look??

Regards

 

[a1ant]

Hi mate,

Could well be a dodgey connection on the 3 way pressure switch.

If you remove the front drivers side wheel, and then undo the screws and remove the plastic wheel arch liner, look directly behind the bumper (to the right) you will see a metal cylinder with a wiring multi-plug attached to the top. Disconnect this and clean the connections. Re try the air-con. If the problem is still there, then you can check the switch with a multimeter, and then check the wiring from the switch etc.

Its also worth checking that you have 12v at the wiring multi-plug on the bottom of the compressor when the a/c light is on. If you have then its likely that the elecro-magnetic clutch on the A/C compressor is at fault.

Hope that helps,
Alan