Radiator Fan

[pajjy]

hello all.

ive a auris t spirit i.6 vvti that has a optitron type instrument gauges,the engine temp gauge is like the fuel gauge that goes up in bars as does the fuel gauge,not a needle type gauge (a pity).

when engine is at normal temp the reading is at the middle bar, as it should be.

i dont know what temp each bar represents in degrees.because when testing if radiator cooling fan is cutting in ok after taking car for a run first to warm it up,then then letting the car tickover till the fan does cut in,which it does ok there is no further rise of bars on the temp gauge above the normal position.i dont think this is fault but the way the system works.

my point is,with a normal gauge you know where the needle position at normal temp,any slight variation will show,and you will have a warning if there is any problem maybe even before the fan cuts in.

not so with the optitron system.you dont know how high the engine temp will rise before the gauge moves up to the next bar.you cant hear the fan cutting whilst driving.not giving much warning if you problems

so am thinking of fitting a extra warning light, showing when the fan cutting in.but i dont know if ther is a seperate temp sensor for the fan and the temp gauge.if they are off the same sensor, then i am stumped.

cant take a feed of the rad fan feed wires as this light would come on when air cons on.

anyone know if the rad fan switch is seperate,cant see much trying to look around rad.looking on toydiy it shows one in the cylinder head.can anyone advise.

years ago when i used tow a caravan,i not only had a fan warning light but fitted a switch to bring the fan on too.very handy when towing caravan in slow traffic.

when having a oil temp gauge when towing it can be worrying how much higher your oil temp goes pulling a caravan.but dont tow now.

any help would be appreciated.

[tavy]

radiator fan is controled by it's own ecu, that is commanded by the engine ecu and the information about the engine temperature is given by the temp. sensor situated on the engine block.

conclusion: playing with the cooling system is not advisable...

[acetip]

radiator fan is controled by it's own ecu, that is commanded by the engine ecu and the information about the engine temperature is given by the temp. sensor situated on the engine block.

conclusion: playing with the cooling system is not advisable...

thanks for that tavy but i was not going to do anything silly.but the answer is the sensor that gives the the gauge reading the same as the one that sensors the temp rise to bring fan on.

like pajjy,i dont like how high the coolant temp would be after the fan comes on before the gauge moving up a bar and giving warning of a problem ie coolant loss.its a shame the normal and more sensetive needle type gauge is not fitted.just think like pajjy a warning light when fan cuts in would give peace of mind.though of course it may never be needed.its like the oil presure gauge you wiill not see it unless there is a problem.but you dont know if the system is working as in a normal type that lights up when turning on ignition and goes off after starting.

this maybe seem petty but these thigs happen.and you ( i do )like peace of mind.

[jettech]

and more sensetive needle type gauge is not fitted

Are you kidding right? Where is the sensitivity in needle gauge showing centigrades on scale 3 cm in length? Dont you think the fan role is to prevent the temp from rising? Check most of the cars with needle "sensitive gauge" if you can see needle mowing up before fan is on. The purpose of the fan is to prevent coolant temp from high rising so it is on well before temp reaches critical point and that is 2-3C above nominal temp.

[pajjy]

and more sensetive needle type gauge is not fitted

Are you kidding right? Where is the sensitivity in needle gauge showing centigrades on scale 3 cm in length? Dont you think the fan role is to prevent the temp from rising? Check most of the cars with needle "sensitive gauge" if you can see needle mowing up before fan is on. The purpose of the fan is to prevent coolant temp from high rising so it is on well before temp reaches critical point and that is 2-3C above nominal temp.

sorry

could not agree with you less.my point is if you have problems causing over heating like a coolant leak then then with the bar type gauge the bar markings are on the fuel side only but the temp rises in jumps just like the fuel readings do.this is not giving reading till it jumps the next position.when testing for the fan cutting in (when ticking over test it takes several mins for this to happen.all the cars ive had with proper gauges you can see small increases.ask people who have diesels and find them slow warming up compared to petrol in this weather.you can see how slow the needle works.i fitted a oil temp gauge to my jetta i had and tested it by sticking the sender in a kettle and found it pretty accurate at boiling point and when switching it off the neede very slowly returned down the scale.all i wish to do is have some means of early warning.a normal gauge is far more sensitive than one thayt goes up in jumps be it a fuel or temp.if you cant see understand that then i am sorry for you.if you have overheating problems whilst drving the fans not going to make much difference to the air speeed through the rad.the fans there for when car is not moving and engine running.it will cut in at a set temp the car moving or not.

[acetip]

and more sensetive needle type gauge is not fitted

Are you kidding right? Where is the sensitivity in needle gauge showing centigrades on scale 3 cm in length? Dont you think the fan role is to prevent the temp from rising? Check most of the cars with needle "sensitive gauge" if you can see needle mowing up before fan is on. The purpose of the fan is to prevent coolant temp from high rising so it is on well before temp reaches critical point and that is 2-3C above nominal temp.

sorry

could not agree with you less.my point is if you have problems causing over heating like a coolant leak then then with the bar type gauge the bar markings are on the fuel side only but the temp rises in jumps just like the fuel readings do.this is not giving reading till it jumps the next position.when testing for the fan cutting in (when ticking over test it takes several mins for this to happen.all the cars ive had with proper gauges you can see small increases.ask people who have diesels and find them slow warming up compared to petrol in this weather.you can see how slow the needle works.i fitted a oil temp gauge to my jetta i had and tested it by sticking the sender in a kettle and found it pretty accurate at boiling point and when switching it off the neede very slowly returned down the scale.all i wish to do is have some means of early warning.a normal gauge is far more sensitive than one thayt goes up in jumps be it a fuel or temp.if you cant see understand that then i am sorry for you.if you have overheating problems whilst drving the fans not going to make much difference to the air speeed through the rad.the fans there for when car is not moving and engine running.it will cut in at a set temp the car moving or not.

could not agree more.

all i am asking is for a means of knowing if the fan has switched on whilest the car is moving.

needle type temp gauges dont goe up in jumps so must be better.

[Mooly]

How many wires to the fan ? The A/C normally cuts it in at low speed, and for engine cooling it runs faster... and I think on the Corolla that was done by a three wire system using offset brushes in the motor which is far more efficient than dropper resistors. If the Auris is the same then you can connect light to the "high speed" feed. If it was a two wire feed and the fan does still run at higher speed for cooling then it's still do-able using an LED and resistor as warning and feeding it via a suitable zener diode that would conduct only when the higher voltage were reached.

[pajjy]

How many wires to the fan ? The A/C normally cuts it in at low speed, and for engine cooling it runs faster... and I think on the Corolla that was done by a three wire system using offset brushes in the motor which is far more efficient than dropper resistors. If the Auris is the same then you can connect light to the "high speed" feed. If it was a two wire feed and the fan does still run at higher speed for cooling then it's still do-able using an LED and resistor as warning and feeding it via a suitable zener diode that would conduct only when the higher voltage were reached.

thank you mooly for that.

will check that out later,cars in garage, the temp there is 3c and -2 outside.the fan computer is at the back of the rad at the top this maybe senses the rad temp.the sensor in the cyl head is for the temp gauge.

thanks again.

[acetip]

How many wires to the fan ? The A/C normally cuts it in at low speed, and for engine cooling it runs faster... and I think on the Corolla that was done by a three wire system using offset brushes in the motor which is far more efficient than dropper resistors. If the Auris is the same then you can connect light to the "high speed" feed. If it was a two wire feed and the fan does still run at higher speed for cooling then it's still do-able using an LED and resistor as warning and feeding it via a suitable zener diode that would conduct only when the higher voltage were reached.

hi mooly

as i am thinking alomg the sane lines pajjy.no electrian but do bits and pieces.

what kind of values do these zener diodes come in.if there such a thing as a adjustable one,which would be handy.

as for the led,i picked up a warning lamp from Halfords,its claimed to be 10 times brighter than a normal lamp,the packet it came in has test button on it so you can check it out before buying.it is very bright,which is just as well as its squarish shape and not suitable for dash mounting.ive already fitted in the switch panel at the bottom of the dash.when testing it,it cant be missed lights up door panel even in sunlight.if you goe back to earlier posting pics

HARD WIRING SAT its shown there.

[Mooly]

With zeners we are into electronics. Zeners come in what are called "preferred values" commonly in the E12 series,

http://www.radio-electronics.com/info/data/resistor/resistor_standard_values.php

I mentioned an LED because that can be made to work correctly for any given voltage across the fan using an appropriate resistor and zener. The Halfords one (you'll have to put a link in) sounds to me as though it's ready to use on 12 volts which means it includes an inbuilt resistor... so it may not be bright enough with a zener.

LED's on there own must NEVER be connected across any Battery or supply, they must have the current limited via a resistor.

If the fan runs on say 6 volts for air con and 12 for full then you want the LED to be OFF on 6 volts. That means a zener of at least 6v needs to be used so that no current flows. We might choose a 6.8 volt one. When 12 volts appears the zener conducts (dropping 6.8v) which leaves 12v minus 6.8v for the LED and resistor. That give 5.2 volts in hand for the LED. The LED drops around 2.2 volts (different colour LED's drop different voltages but 2.2v is a safe working average). So we have 5.2 - 2.2 which is 3 volts.

This 3 volts need to be dropped across a resistor. The LED will take say 5 or 10 milliamps so the resistor is R=V/I which is 3/0.01 or 300 ohm. The values are not at all critical... what's important is first knowing the working voltages on the fan. Also the 12 volts will be higher when the engine is running, certainly nearer 14 in most conditions which helps. The values I worked are just an example.

LED's zeners and resistors cost buttons, even at places like Maplin.

Pages of them, all shapes sizes and colours and clips etc

http://www.maplin.co.uk/Search.aspx?criteria=led

http://www.maplin.co.uk/Search.aspx?criteria=Resistor

http://www.maplin.co.uk/Search.aspx?criteria=Zener+Diode

[acetip]

With zeners we are into electronics. Zeners come in what are called "preferred values" commonly in the E12 series,

http://www.radio-electronics.com/info/data/resistor/resistor_standard_values.php

I mentioned an LED because that can be made to work correctly for any given voltage across the fan using an appropriate resistor and zener. The Halfords one (you'll have to put a link in) sounds to me as though it's ready to use on 12 volts which means it includes an inbuilt resistor... so it may not be bright enough with a zener.

LED's on there own must NEVER be connected across any battery or supply, they must have the current limited via a resistor.

If the fan runs on say 6 volts for air con and 12 for full then you want the LED to be OFF on 6 volts. That means a zener of at least 6v needs to be used so that no current flows. We might choose a 6.8 volt one. When 12 volts appears the zener conducts (dropping 6.8v) which leaves 12v minus 6.8v for the LED and resistor. That give 5.2 volts in hand for the LED. The LED drops around 2.2 volts (different colour LED's drop different voltages but 2.2v is a safe working average). So we have 5.2 - 2.2 which is 3 volts.

This 3 volts need to be dropped across a resistor. The LED will take say 5 or 10 milliamps so the resistor is R=V/I which is 3/0.01 or 300 ohm. The values are not at all critical... what's important is first knowing the working voltages on the fan. Also the 12 volts will be higher when the engine is running, certainly nearer 14 in most conditions which helps. The values I worked are just an example.

LED's zeners and resistors cost buttons, even at places like Maplin.

Pages of them, all shapes sizes and colours and clips etc

http://www.maplin.co.uk/Search.aspx?criteria=led

http://www.maplin.co.uk/Search.aspx?criteria=Resistor

http://www.maplin.co.uk/Search.aspx?criteria=Zener+Diode

hi mooly

thanks for that.when i brought the LED the packet had been opened and instructons missing,and as it was the last one Halfords had i brought it anyway.so i phoned them for advice as was told it was ok up to 15v.it does not seem this project is going to be as simple as i hoped,will go softly softly,there no rush.maybe PAJJY wil sort it and post results.

[Daveyonthemove]

If you have an Android Phone, you can have the engine temp on display for as little as £25 and no cutting wires.

Top of the screen is Coolant temp (Dial or digital readout)

Middle of the screen is Air Intake temp (Dial or digital readout)

Bottom of the screen is Ambient air temp (Dial or digital readout)

[Daveyonthemove]

Sorry for the quality of the pic, the camera was left in the car and steamed up as soon as i tried to use it.

[pajjy]

If you have an Android Phone, you can have the engine temp on display for as little as £25 and no cutting wires.

Top of the screen is Coolant temp (Dial or digital readout)

Middle of the screen is Air Intake temp (Dial or digital readout)

Bottom of the screen is Ambient air temp (Dial or digital readout)

hi daveyonthemove.

can you explainn to an old f**t how the hell does it do that.you say its wirless.

the lomger i live the less i seem to know.what is intake temp,is it cabin temp. you ask if i have one.have one? cant even spell it.

[Daveyonthemove]

LOL, technology eh??

Android is the operating software on a phone (think windows on your PC) and various phones now run on it, mostly new HTC handsets (like mine) and its very flexible and open to developers.

My Android handset has an application on it called 'Torque' which connects to a car using bluetooth and a OBDII scanner (bought for under £23 on ebay).

The app' connects to the OBD reader using blutetooth and allows me to monitor a large amount of data (like the above pic shows) as well as scanning for fault codes, interrogating them for an answer as to what they mean, and also the ability to clear them. This is excellent when you consider the cost of a dealer scanning the ECU.

I think the intake temp is the temp taken from the MAF sensor, although i could be wrong. Its not the interior temp i don't think.

I usually only check the BHP/Torque live readings but its good to know that you can check temps if you are unhappy with the digital display.

Hope that helps a bit.

Dave

[pajjy]

LOL, technology eh??

Android is the operating software on a phone (think windows on your PC) and various phones now run on it, mostly new HTC handsets (like mine) and its very flexible and open to developers.

My Android handset has an application on it called 'Torque' which connects to a car using bluetooth and a OBDII scanner (bought for under £23 on ebay).

The app' connects to the OBD reader using blutetooth and allows me to monitor a large amount of data (like the above pic shows) as well as scanning for fault codes, interrogating them for an answer as to what they mean, and also the ability to clear them. This is excellent when you consider the cost of a dealer scanning the ECU.

I think the intake temp is the temp taken from the MAF sensor, although i could be wrong. Its not the interior temp i don't think.

I usually only check the BHP/Torque live readings but its good to know that you can check temps if you are unhappy with the digital display.

Hope that helps a bit.

Dave

hi again

my phone is a motorola rav something or other.had it years,just getting the hang of it.nice big numbers for my sausage like finges.has bluetooth, but have gagdet clip to sunvisor for voice dialing etc.thanks for advice.

hows the throttle on car,still behaving its self.

[Daveyonthemove]

Car is running perfectly now.

Dealers had a good look at common faults (EGR etc) and reset the ECU values. Seems to have done the trick

[acetip]

With zeners we are into electronics. Zeners come in what are called "preferred values" commonly in the E12 series,

http://www.radio-electronics.com/info/data/resistor/resistor_standard_values.php

I mentioned an LED because that can be made to work correctly for any given voltage across the fan using an appropriate resistor and zener. The Halfords one (you'll have to put a link in) sounds to me as though it's ready to use on 12 volts which means it includes an inbuilt resistor... so it may not be bright enough with a zener.

LED's on there own must NEVER be connected across any battery or supply, they must have the current limited via a resistor.

If the fan runs on say 6 volts for air con and 12 for full then you want the LED to be OFF on 6 volts. That means a zener of at least 6v needs to be used so that no current flows. We might choose a 6.8 volt one. When 12 volts appears the zener conducts (dropping 6.8v) which leaves 12v minus 6.8v for the LED and resistor. That give 5.2 volts in hand for the LED. The LED drops around 2.2 volts (different colour LED's drop different voltages but 2.2v is a safe working average). So we have 5.2 - 2.2 which is 3 volts.

This 3 volts need to be dropped across a resistor. The LED will take say 5 or 10 milliamps so the resistor is R=V/I which is 3/0.01 or 300 ohm. The values are not at all critical... what's important is first knowing the working voltages on the fan. Also the 12 volts will be higher when the engine is running, certainly nearer 14 in most conditions which helps. The values I worked are just an example.

LED's zeners and resistors cost buttons, even at places like Maplin.

Pages of them, all shapes sizes and colours and clips etc

http://www.maplin.co.uk/Search.aspx?criteria=led

http://www.maplin.co.uk/Search.aspx?criteria=Resistor

http://www.maplin.co.uk/Search.aspx?criteria=Zener+Diode

[acetip]

With zeners we are into electronics. Zeners come in what are called "preferred values" commonly in the E12 series,

http://www.radio-electronics.com/info/data/resistor/resistor_standard_values.php

I mentioned an LED because that can be made to work correctly for any given voltage across the fan using an appropriate resistor and zener. The Halfords one (you'll have to put a link in) sounds to me as though it's ready to use on 12 volts which means it includes an inbuilt resistor... so it may not be bright enough with a zener.

LED's on there own must NEVER be connected across any battery or supply, they must have the current limited via a resistor.

If the fan runs on say 6 volts for air con and 12 for full then you want the LED to be OFF on 6 volts. That means a zener of at least 6v needs to be used so that no current flows. We might choose a 6.8 volt one. When 12 volts appears the zener conducts (dropping 6.8v) which leaves 12v minus 6.8v for the LED and resistor. That give 5.2 volts in hand for the LED. The LED drops around 2.2 volts (different colour LED's drop different voltages but 2.2v is a safe working average). So we have 5.2 - 2.2 which is 3 volts.

This 3 volts need to be dropped across a resistor. The LED will take say 5 or 10 milliamps so the resistor is R=V/I which is 3/0.01 or 300 ohm. The values are not at all critical... what's important is first knowing the working voltages on the fan. Also the 12 volts will be higher when the engine is running, certainly nearer 14 in most conditions which helps. The values I worked are just an example.

LED's zeners and resistors cost buttons, even at places like Maplin.

Pages of them, all shapes sizes and colours and clips etc

http://www.maplin.co.uk/Search.aspx?criteria=led

http://www.maplin.co.uk/Search.aspx?criteria=Resistor

http://www.maplin.co.uk/Search.aspx?criteria=Zener+Diode

hi mooly.

havent had a chance till this morning to look at fan setup as had daughter over from paris staying.

anyway the fan ecu is mounted on the back of the rad and i think it senses coolant temp as well.unlike other methods that have temp switch at the bottom of the rad.

3 wirs enter this ecu. i earth, 1 from another ecu which could be the one for aircon, and 1 from ignition via a relay. 2 wires leave ecu for the fan motor 1 pos, i earth.

so there is no way i can take a direct feed for a warning lamp without showing both with aircon and cooling.

so i am going (sometime)check what voltage i get from feed to fan motor in aircon mode.fingers crossed there is a difference when between that and coolant mode.all being well i can use your advice using a zena diode.

thanks again.