radiator fan diagnostics

I have a 2003 panorama c3. I am having trouble with the radiator fan / over heating. the temp gauge goes from 3 bars straight into the red when the fan stops working. the weird thing is, sometimes the fan works when the car is hot or the aircon is on and sometimes it doesn't. I can tell it is working sometimes because it continues to run after I trun the car off. I don't know if it is related ( I don't know how it could be) but sometimes when I turn the car on the aircon is turned on even though it wasn't on when I switched the car off. also sometimes when I return to the car the wipers are in the vertical position. what are some steps to diagnose the problem ( or is my car haunted lol)?

Welcome to the forum paulmelb

paulmelb wrote:what are some steps to diagnose the problem

I think you have 2 problems.

paulmelb wrote:but sometimes when I turn the car on the aircon is turned on even though it wasn't on when I switched the car off.

This is normal.

paulmelb wrote:I am having trouble with the radiator fan / over heating. the temp gauge goes from 3 bars straight into the red when the fan stops working. the weird thing is, sometimes the fan works when the car is hot or the aircon is on and sometimes it doesn't.

The BSI (fuse box in the glove box) and Engine ECU both can inhibit the aircon and have a hand in the engine cooling fan.

To diagnose what is being inhibited, enabled and why, you need to use the lexia clone tool to look at the error codes and the status of the various things that control the engine cooling fan including load shedding and air con enable and inhibit.
Our lexia topic is here https://citroenc3owners.com/citroen-c3-t ... -t655.html

Overheating - diagnose if its actually getting too hot or just not reading the temperature correctly. It may just be a faulty sensor or damaged wiring to the sensor. If you just wanted to change the sensor for a start, enter your registration number or C3 details into the search box at euro car parts to find the right one for your model and year C3.

paulmelb wrote:also sometimes when I return to the car the wipers are in the vertical position

This is a different problem and could be BSI or COM2000 (stalks by the steering wheel) related. You should still use the same [url=ttp://www.amazon.co.uk/gp/product/B00L172SZ6/ ... BGZWXLHFKY]lexia tool[/url] but monitor signals from the com2000 and diagnose from there.

paulmelb wrote:what are some steps to diagnose the problem

Its all computer diagnostics because the problems you have are all run by various computers. You may find its a sensor, poor connection or even a damaged ECU You could try another engine temperature sensor and look at the wiring to the ECU and the ECU plug while you are replacing the sensor?