My question is ; how do I test both the main cooling fan and Aircon condenser fans and if they are operating on full speed? And test the sensor that drives their speed. That is ,if they are sensor driven and multi speed?

The story so far

Took the XKR to a mechanic yesterday to follow up after my hot day / stuck in traffic, apparent very momentary overheat, with Aircon on.
Haven't really been game to drive it much since that.
Anyways , drove over there yesterday morning , ambient around 18 deg C and I note that it doesn't and hasn't since had an issue the few times I have driven it since( Including today)
Note , that doesn't include a 35 degree day , stuck in traffic , with the Aircon on.

Trip to mech turned out to be a bit of waste of time.

1. Their loan car , that I needed for the day wasn't back.
2. Being a numpty, I had left my driving license in my wallet in the desk at work. No license proof, no loan car. Fair do's .I could book it back in but might like to work it out myself.
3. On review of service records we ascertained that both the water pump and the thermostat had been replaced within the last couple of years. Not that we can completely discount them , but
4. We came to the conclusion that it may be a faulty temperature sensor that drives the fans or faulty fans , either causing them not to run at full speed. Pardon my ignorance but on a 2000 XKR is the main cooling fan a viscous drive type or an electric?
5. I am guessing the other one is for the AC condenser.

How would I carry out a test of all these components

Many Thanks

Pete

 

Your two electric fans are controlled by the ECM through a fan module located at the lower left side of the radiator. They have two speeds. In low speed the relays operate to deliver battery voltage through the fan motors in series. In high the relays operate to deliver battery voltage to each of the fan motors.

Both fans should operate in low mode anytime the AC is on. That is the first test. If the fans do not operate the relays would be first suspect. If only one does then the other motor is suspect.

Coolant temperature also operates the fans from a sensor located in the cross over pipe from the top radiator connection. You can measure the engine head temp with an IR temp gauge to see if the fans come on high speed at about 92* C.

 

See Whitexkr's website about Realguage. His install calibration procedure shows how to use a variable potentiometer (pot) to fool car into thinking temp sensor reads various engine temps. Without realguage you will have to have obdcc reader pluged in. Note temp reading when fans come on. (Just validated they trip and they work) . Measure pot resistance when they trip. Use that as reference to measure resistance of thermosensor when you heat it in water to that temp. Frankly sensors are rather cheap may be easier to just replace it if in question.