09 Prostar AC problem

Compressors are supposed to cycle. Certain conditions need to be met for the compressor to operate. Static pressure with the system off needs to be high enough, which indicates the charge is good and ambient air temp isn't too low. Usually that is taken care of by the trinary switch. Next is the thermostatic switch inside your evaporator core. Once the temperature in the core gets to around freezing, it will kick the compressor out to prevent the core from freezing up. What is the outside air temp and what is the air temp coming out of your vents at max a/c and high fan speed?

 

We see often the magnetic coil that engages the clutch gets weak once the compressor is hot with the engine and can no longer generate a strong enough magnetic field to engage the clutch. I am not aware of any icons on the display that are related to compressor operation.

 

For the clutch, this is how I do it. This is dangerous, so be warned and do this at your own risk! With the engine running, turn on the a/c and let it run until it quits working. Now, I have a laptop hooked up so I know when it is actually suppose to be on. When it is suppose to be on, but it isn't, I will tap the face of the clutch with small hammer. If it engages, then I know the clutch is NFG. Since the fan is spinning and belts are right there turning it is dangerous so becareful! I have never replaced the clutch on a Sanden style compressor, always only replaced the whole thing.

I found this regarding the asterisk.


DESCRIPTION


An asterisk or star displayed on the lower right quadrant of dash information display.
SYMPTOMS

There is no failure related to this asterisk-it is just visible in the display.

TROUBLESHOOTING

No troubleshooting is required as there is no failure.

RESOLUTION

To identify the reason for the asterisk you can turn the display button so the lower right quadrant is highlighted, then press the button to toggle to the next screen. The asterisk symbol tells you that there is an additional message available. This is most likely going to be a compass module but following these instructions will allow you to see what that message is.