Rad Cooling Fan Override With No Glow Warning Light When Off

[Penelope Stopit]

I've not been able to find a decent simple circuit that will allow the manual switching on of a radiator cooling fan and has a warning light to inform the driver that there is power to the fan motor

The majority of circuits have a problem........When the fan switch is in the off position the fan motor is driven by air hitting the front of the vehicle and acts as a generator which in turn causes the fan warning light to annoyingly glow

This simple circuit solves the problem



Shown with an LED, a normal bulb/reflector warning light will obviously do the same job

Edited by Penelope Stopit on Friday 7th June 13:34

[magpies]

If using LED lamp then CarBuilderSolutions do a simple piggyback resistor wire that allows dim off and bright on (or visa versa) settings

[citizen smith]

Penelope Stopit said:

I've not been able to find a decent simple circuit that will allow the manual switching on of a radiator cooling fan and has a warning light to inform the driver that there is power to the fan motor

The majority of circuits have a problem........When the fan switch is in the off position the fan motor is driven by air hitting the front of the vehicle and acts as a generator which in turn causes the fan warning light to annoyingly glow

This simple circuit solves the problem

There is a solution that utilizes the V/X Cavalier MK3 Hatchback Wiper Switch in the "Chimaera Pages" website, you can either use the LED on the Dashboard or install your own on the Steering Column assembly.

[Penelope Stopit]

magpies said:

If using LED lamp then CarBuilderSolutions do a simple piggyback resistor wire that allows dim off and bright on (or visa versa) settings

A resistor won't achieve anything close to what the above circuit achieves and there is every possibility that you have misunderstood something,
It is not possible to wire a resistor into the above circuit and notify the driver of a voltage being present at the fan motor

[Penelope Stopit]

citizen smith said:

Penelope Stopit said:

I've not been able to find a decent simple circuit that will allow the manual switching on of a radiator cooling fan and has a warning light to inform the driver that there is power to the fan motor

The majority of circuits have a problem........When the fan switch is in the off position the fan motor is driven by air hitting the front of the vehicle and acts as a generator which in turn causes the fan warning light to annoyingly glow

This simple circuit solves the problem

There is a solution that utilizes the V/X Cavalier MK3 Hatchback Wiper Switch in the "Chimaera Pages" website, you can either use the LED on the Dashboard or install your own on the Steering Column assembly.

Yes any switch can be used/fitted anywhere

This circuit prevents the windmill effect generated voltage from glowing the warning light

[Penelope Stopit]

I have shown an LED as that is what my first solution requester wanted to use

A bulb will also work without a problem

It's all about stopping the glowing warning light

[Penelope Stopit]

citizen smith said:

Penelope Stopit said:

I've not been able to find a decent simple circuit that will allow the manual switching on of a radiator cooling fan and has a warning light to inform the driver that there is power to the fan motor

The majority of circuits have a problem........When the fan switch is in the off position the fan motor is driven by air hitting the front of the vehicle and acts as a generator which in turn causes the fan warning light to annoyingly glow

This simple circuit solves the problem

There is a solution that utilizes the V/X Cavalier MK3 Hatchback Wiper Switch in the "Chimaera Pages" website, you can either use the LED on the Dashboard or install your own on the Steering Column assembly.

Ok, I've visited Chimaera Pages and the solution that's shown there is not a solution, the circuit shown has a warning light that informs the driver that the override switch is in the on position, it doesn't inform the driver that there is a supply and earth at the motor

[Penelope Stopit]

magpies said:

If using LED lamp then CarBuilderSolutions do a simple piggyback resistor wire that allows dim off and bright on (or visa versa) settings

This



Has nothing to do with this



You have definitely misunderstood something

[phillpot]

Penelope Stopit said:

magpies said:

If using LED lamp then CarBuilderSolutions do a simple piggyback resistor wire that allows dim off and bright on (or visa versa) settings

This

Would I need an extra relay (or two) if using that?

[citizen smith]

Penelope Stopit said:

citizen smith said:

Penelope Stopit said:

I've not been able to find a decent simple circuit that will allow the manual switching on of a radiator cooling fan and has a warning light to inform the driver that there is power to the fan motor

The majority of circuits have a problem........When the fan switch is in the off position the fan motor is driven by air hitting the front of the vehicle and acts as a generator which in turn causes the fan warning light to annoyingly glow

This simple circuit solves the problem

There is a solution that utilizes the V/X Cavalier MK3 Hatchback Wiper Switch in the "Chimaera Pages" website, you can either use the LED on the Dashboard or install your own on the Steering Column assembly.

Ok, I've visited Chimaera Pages and the solution that's shown there is not a solution, the circuit shown has a warning light that informs the driver that the override switch is in the on position, it doesn't inform the driver that there is a supply and earth at the motor

It worked for a simple person like me, but I only wanted to know when the fan was running.

[Penelope Stopit]

citizen smith said:

It worked for a simple person like me, but I only wanted to know when the fan was running.

And this is the reason why I came up with a solution
That Chimaera Pages circuit doesn't let the driver know anything more than that she/he has switched the fan on

The circuit I have shown does let the driver know that the switch is on and there is a voltage supplied to the motor, Ok it's not bomb proof but as close as I can get it while keeping it simple (it takes much more to show the motor is rotating at full speed). Once a length of 2 core cable has been run from the fan motor to the fusebox area the rest of the work is easy

The other benefit of the circuit is that it informs the driver when the otter switch has switched the fan on

Edited by Penelope Stopit on Friday 7th June 17:09

[citizen smith]

Penelope Stopit said:

citizen smith said:

It worked for a simple person like me, but I only wanted to know when the fan was running.

And this is the reason why I came up with a solution
That Chimaera Pages circuit doesn't let the driver know anything more than that she/he has switched the fan on

The circuit I have shown does let the driver know that the switch is on and there is a voltage supplied to the motor, Ok it's not bomb proof but as close as I can get it while keeping it simple (it takes much more to show the motor is rotating at full speed). Once a length of 2 core cable has been run from the fan motor to the fusebox area the rest of the work is easy

The other benefit of the circuit is that it informs the driver when the otter switch has switched the fan on

Edited by Penelope Stopit on Friday 7th June 17:09

My car had the MBE Engine Management Kit fitted, that did not rely on the Radiators Otter Switch.

[Penelope Stopit]

citizen smith said:

My car had the MBE Engine Management Kit fitted, that did not rely on the Radiators Otter Switch.

MBE System is not a problem, a small modification will make it compatible

[stevesprint]

Penelope Stopit said:

The majority of circuits have a problem........When the fan switch is in the off position the fan motor is driven by air hitting the front of the vehicle and acts as a generator which in turn causes the fan warning light to annoyingly glow

This simple circuit solves the problem .....

Penelope Stopit

Very simple & effective, thanks.

Why didn’t I think of an extra relay to kill the fans warming lamp's negative while the fans are not running, I’ve had glowing warning lamps during fans overrun on motorways for nearly thirty years. Your extra relay is even more meaningful to me as I always run my fans with 2 speeds (slow speed in series, full speed in parallel) and therefore my lamp also glows with the fans 1st slow speed.

Thanks for sharing your very neat idea.

[Penelope Stopit]

stevesprint said:

Penelope Stopit said:

The majority of circuits have a problem........When the fan switch is in the off position the fan motor is driven by air hitting the front of the vehicle and acts as a generator which in turn causes the fan warning light to annoyingly glow

This simple circuit solves the problem .....

Penelope Stopit

Very simple & effective, thanks.

Why didn’t I think of an extra relay to kill the fans warming lamp's negative while the fans are not running, I’ve had glowing warning lamps during fans overrun on motorways for nearly thirty years. Your extra relay is even more meaningful to me as I always run my fans with 2 speeds (slow speed in series, full speed in parallel) and therefore my lamp also glows with the fans 1st slow speed.

Thanks for sharing your very neat idea.

You very likely didn't think of it due to the same reason as I for a long time didn't think of it, that reason being that we are often deeply involved in complicated things and overlook the obvious solutions for the simple things

I'm very happy that you will find a use for it and be able to adapt it to suit your 2 fan set-up

I only now have thought about using a double pole single throw switch to achieve close to the same solution for a single fan set-up but the warning light wouldn't inform the driver that the vehicles own fan switch or ECU controlled switching had switched the fan on

Yamas

[stevesprint]

Back in the day on my TR7 V8 with one large cooling fan I used 205GTi fan resistors held on with Terry clip for the fans slow speed but I guess you can use any resistor with a high enough wattage.


205GTI Fan resistor
https://spoox.co.uk/peugeot-205/6139-peugeot-205-g...

You can see my change over relay here, plus there’s a list of 2 speed otter M22 x 1.5mm switches
https://www.pistonheads.com/gassing/topic.asp?h=0&...

I’ve now reprogrammed the 14CUX A/C outputs to control my cooling fans in two stages at configurable temperature threshold.

[magpies]

Penelope Stopit said:

magpies said:

If using LED lamp then CarBuilderSolutions do a simple piggyback resistor wire that allows dim off and bright on (or visa versa) settings

A resistor won't achieve anything close to what the above circuit achieves and there is every possibility that you have misunderstood something,
It is not possible to wire a resistor into the above circuit and notify the driver of a voltage being present at the fan motor

I totally had the wrong end of the stick … ignore my previous

[Penelope Stopit]

stevesprint said:

Back in the day on my TR7 V8 with one large cooling fan I used 205GTi fan resistors held on with Terry clip for the fans slow speed but I guess you can use any resistor with a high enough wattage.


205GTI Fan resistor
https://spoox.co.uk/peugeot-205/6139-peugeot-205-g...

You can see my change over relay here, plus there’s a list of 2 speed otter M22 x 1.5mm switches
https://www.pistonheads.com/gassing/topic.asp?h=0&...

I’ve now reprogrammed the 14CUX A/C outputs to control my cooling fans in two stages at configurable temperature threshold.

Nice, I prefer the resistor method to wiring motors in series, if one motor fails, both fail when in series

[Penelope Stopit]

magpies said:

Penelope Stopit said:

magpies said:

If using LED lamp then CarBuilderSolutions do a simple piggyback resistor wire that allows dim off and bright on (or visa versa) settings

A resistor won't achieve anything close to what the above circuit achieves and there is every possibility that you have misunderstood something,
It is not possible to wire a resistor into the above circuit and notify the driver of a voltage being present at the fan motor

I totally had the wrong end of the stick … ignore my previous

I guessed you had, no problem