Technical Radiator fan not working when water is above 88 deg

[deafmazter]

Anyone have any idea why my radiator fan no longer turns on at warm engine?
Is about a punto hgt, the radiator is now connected to my low beam for a while so I can turn it on when I'm in traffic. For now an emergency solution.

Relay and fuses have already been replaced. Any ideas?

 

[judderbar]

Anyone have any idea why my radiator fan no longer turns on at warm engine?
Is about a punto hgt, the radiator is now connected to my low beam for a while so I can turn it on when I'm in traffic. For now an emergency solution.

Relay and fuses have already been replaced. Any ideas?

On the diesel first speed fan starts at 90-94C. and off at 85-89. Second if fitted starts at 95-99C and off at 90-94

Diesel thermostat opening begins at 86-90 and is fully open at 101 to 105.

On the petrol engine First speed fan starts at 98C. Second speed fan if fitted starts at 101C.

 

[deafmazter]

On the diesel first speed fan starts at 90-94C. and off at 85-89. Second if fitted starts at 95-99C and off at 90-94

Diesel thermostat opening begins at 86-90 and is fully open at 101 to 105.

On the petrol engine First speed fan starts at 98C. Second speed fan if fitted starts at 101C.

Iknow mate. But how does the fan know to turn on at some temp? Some cars have 2 sensors, does the hgt have this tho?

In fact, I have the idea that the only temperature sensor I see is no longer transmitting the readings properly. Can that be correct or does the hgt have two sensors like some manufacturers.

So 1 for the cooling water display and 1 for the radiator fan.

 

[judderbar]

Iknow mate. But how does the fan know to turn on at some temp? Some cars have 2 sensors, does the hgt have this tho?

In fact, I have the idea that the only temperature sensor I see is no longer transmitting the readings properly. Can that be correct or does the hgt have two sensors like some manufacturers.

So 1 for the cooling water display and 1 for the radiator fan.

there is only one sensor. resistance 2500 ohms at 20c and 186ohms at 100C

 

[deafmazter]

there is only one sensor. resistance 2500 ohms at 20c and 186ohms at 100C

Yes correct, I replaced this one and problem is not solved (it is good because it was measured through) Furthermore, the relay was replaced, do you have any idea what else it could be?

The fan does work, it just doesn't get a signal that it should switch on when the engine is too hot.

 

[porta]

Yes correct, I replaced this one and problem is not solved (it is good because it was measured through) Furthermore, the relay was replaced, do you have any idea what else it could be?

The fan does work, it just doesn't get a signal that it should switch on when the engine is too hot.

If you’re going by the gauge, it’s really not that accurate to read the temperature…if you fitted new switch/relay let it get to the 90-94 range and see if it kicks in before assuming an issue.
My Panda gauge says about 96 before the fan cuts in, on the Polaris Ranger it read 98 and was telling me to switch engine off
If you have a multimeter, get a thermal probe and measure temperature that way, on the panda, the thermal probe, on bottom hose/radiator area says 92*C, on the ranger, the probe read 94…the sensor was faulty and it really wasn’t overheating

 

[deafmazter]

If you’re going by the gauge, it’s really not that accurate to read the temperature…if you fitted new switch/relay let it get to the 90-94 range and see if it kicks in before assuming an issue.
My Panda gauge says about 96 before the fan cuts in, on the Polaris Ranger it read 98 and was telling me to switch engine off
If you have a multimeter, get a thermal probe and measure temperature that way, on the panda, the thermal probe, on bottom hose/radiator area says 92*C, on the ranger, the probe read 94…the sensor was faulty and it really wasn’t overheating

Yes the sensor is new and just fine! It has just the number of ohms on it that is in the prescribed tables. The problem lies in the fact that the coolfan is not getting a signal to turn on. This is probably in the ecu because the coolfan is connected to my low beam lights, so when I turn it on the fan comes on. So the fan just works! All relays and fuses are measured and are not broken. Just like the sensor.

The sensor (actually switch)that I'm going to put in extra opens at 85 degrees (so runs a current that now comes from the low beam lights)
So that the coolfan still turns on and it no longer has to be done manually.

 

[judderbar]

Yes correct, I replaced this one and problem is not solved (it is good because it was measured through) Furthermore, the relay was replaced, do you have any idea what else it could be?

The fan does work, it just doesn't get a signal that it should switch on when the engine is too hot.

on the petrol engines if you start the car with the sensor disconnected the fan should run. Probably the same for the diesel. My french manual says the diesel sensor is supplied with 5 V.

But you were saying the temperature gauge is not working correctly? Could be telling you something about the wiring or sensor?

Have you confirmed the fan will work when the negative (earthed) connection of the relay is grounded?

 

[deafmazter]

on the petrol engines if you start the car with the sensor disconnected the fan should run. Probably the same for the diesel. My french manual says the diesel sensor is supplied with 5 V.

But you were saying the temperature gauge is not working correctly? Could be telling you something about the wiring or sensor?

Have you confirmed the fan will work when the negative (earthed) connection of the relay is grounded?

Temp sensor is okay, measured it and readings are just right!
K myself think it's in the ECU. I have done the following:
- Measured the relays and they all work fine!
- Installed a new temperature sensor and measured it!
- Checked the fan and its resistance, they are doing fine.
- Checked if the fan is getting voltage, this does not happen so there is something wrong here but what? The temperature sensor gives a signal to the ecu which controls the relays. The temperature sensor and relay just work, so I'm afraid it's in the wiring of the ecu or the ecu itself....

And what do you mean with checking or the relay is grounded?

 

[judderbar]

Temp sensor is okay, measured it and readings are just right!
K myself think it's in the ECU. I have done the following:
- Measured the relays and they all work fine!
- Installed a new temperature sensor and measured it!
- Checked the fan and its resistance, they are doing fine.
- Checked if the fan is getting voltage, this does not happen so there is something wrong here but what? The temperature sensor gives a signal to the ecu which controls the relays. The temperature sensor and relay just work, so I'm afraid it's in the wiring of the ecu or the ecu itself....

And what do you mean with checking or the relay is grounded?

I was wondering if you can confirm the fan works by activating the relay when it is plugged into the fusebox.

 

[jackwhoo]

With Petrol engine fan doesn't switch on until coolant temperature in the high 90s degrees centigrade

 

[deafmazter]

I was wondering if you can confirm the fan works by activating the relay when it is plugged into the fusebox.

Yes, when I unplugged the relay the fan stops!

 

[deafmazter]

With Petrol engine fan doesn't switch on until coolant temperature in the high 90s degrees centigrade

I know buddy, but my engine is overcooking and the fan won’t turn on so big problem

 

[jackwhoo]

Does the radiator fan come on when the coolant reaches 100 degrees ?
Can you use a scan tool to read the coolant temperature from the engine ecu?

 

[jackwhoo]

I know buddy, but my engine is overcooking and the fan won’t turn on so big problem

Do you mean the coolant is boiling even though the coolant cap is on and the cooling system is pressurised?

 

[jackwhoo]

Hi,
I think there may be a culture difference .....please do not call me buddy or mate as I have never met you in person.

I have reread the compete thread and think you are correct to suspect the wire from the ecu to the fan relay - check it for continuity , it may well be the problem .

Using scan tool live data attempt to read the coolant temperature from the engine ecu to check ecu is receiving signal from coolant temperature sensor.

Kind wishes

Jack

 

[deafmazter]

Do you mean the coolant is boiling even though the coolant cap is on and the cooling system is pressurised?

Yes. The fan won’t come on no matters or the temp is above 100 deg. Even I can’t turn the fan on with MES.. The temp of the coolant water is visable in MES also, the ecu + sensor is working correctly

 

[deafmazter]

Hi,
I think there may be a culture difference .....please do not call me buddy or mate as I have never met you in person.

I have reread the compete thread and think you are correct to suspect the wire from the ecu to the fan relay - check it for continuity , it may well be the problem .

Using scan tool live data attempt to read the coolant temperature from the engine ecu to check ecu is receiving signal from coolant temperature sensor.

Kind wishes

Jack

Sorry, is a Dutch thing haha. I am long thankful that you are thinking with me!

 

[jackwhoo]

Hi,
In that case definately check the wire from the ecu to the relay is intact .
Normally the ecu grounds the negative terminal of the relay solenoid to turn the relay on.
The solenoid in the relay positive terminal normally has battery voltage with ignition on.

 

[deafmazter]

Hi,
In that case definately check the wire from the ecu to the relay is intact .
Normally the ecu grounds the negative terminal of the relay solenoid to turn the relay on.
The solenoid in the relay positive terminal normally has battery voltage with ignition on.

I will do!
Do you know which colour it is or do you have a wiring diagram?