Hey,

Does anyone know where the thermostat for AC is located on a 2001 1.2 16v punto?

Thanks,
Jon

thermostat for AC?

Do you mean Preasure switch?

oldhammer said:

thermostat for AC?

Do you mean Preasure switch?

Click to expand...

No not the pressure switch - I know where that is.

According to my haynes manual there's a thermostat in the AC circuit diagram labled 92 in the attached picture.

Hi,

The one that cycles the compressor is attached to the evaporator. Cycles the compressor on at temps above 5oC and off at something like 3oC (don't have the exact data Infront of me at the moment but I'm pretty sure I'm close as most systems are the same)

Alan

Hi,

I have checked and I was close, off at 3.5oC on at 5oC

Alan

a1ant said:

Hi,

I have checked and I was close, off at 3.5oC on at 5oC

Alan

Click to expand...

Hi Alan,

Thanks for the reply and checking. I was going to probe the thermostat to ensure it's allowing the compressor to run but if it's on the evaporator then it'll be a right pain as I assume its deep in the dash.

You seem to be the go to guy regarding ac around here Do you have any information regarding the function of each 5 pins of the pressure sensor? I know the voltages but can't interpret them.

I'll post a link in a sec to an alfa forum post I saw a similar pinout but I'm not convinced it's the same/right.

Thanks,

Jon

Hi mate,

The alfa one is similar but not the same.

Pin 1 - White and green
Pin 2 - Light blue and Brown
Pin 3 - Light blue and White
Pin 5 - White and Black
Pin 6 - Black and Pink

There should be continuity between pins 2 and 5. these 2 pins deal with over and under pressure. If the pressure is either over 28 bar or under 2.45bar it will break continuity between the two pins and cut the compressor.

1 and 6 will have continuity when the pressure rises above 15bar and this will turn on the first speed of the cooling fan.

3 and 6 will have continuity when the pressure is above 20 bar and will turn on the second speed cooling fan.

The frost stat that is located on the evaporator comes before the 4 stage pressure switch.

When the AC is switched on, the signal goes to the thermostat, then if the thermostat wants the compressor to engage, the signal goes direct the pin 2 on the pressure switch.

Hope that makes sense.

Alan

Hey Alan,

Thank you very much for the help! That makes sense. I've got something to go on now to fix the ac

Jon

For the sake of completeness here's a link to a new related thread: https://www.fiatforum.com/punto-ii/354329-p0480-t7-relay.html