Fan "on" light

[fool73]

I recently fitted a Revotec fan kit with thermostat in the top hose.
I wanted to know when it comes on (partly so I could set an appropriate temp for it to come on), so I wired a lamp to the positive wire on the fan side of the relay.
The lamp comes on fine when the fan runs, but I also noted that it starts glowing after about 30mph and gets brighter the faster I go (even though the fan isn't on).
I assume the fan must be spinning due to the force of air due to the car moving and acting as a generator.
Is there anything I can do to the circuit so the bulb only lights when the fan is turned on (e.g what if I connected to the thermostat side of the relay ?)

[Always wanted a Stag]

I have a Kenlowe and fitted a warning light to tell me when it's running.
I wired the warning light into the relay so that it's activated when the relay receives the voltage to connect the fan to the high output supply.

Hope this makes sense and is helpful

Best regards

Paul

[NickA]

I can see when my fan comes on.. The volt meter reading drops...

[Jeff]

My Kenlowe fan has never come on since I refitted the viscous fan.

[wilf]

To stop back-EMF from making the "fan on" bulb glow dimly, you need to fit a diode. Not knowing your exact circuitry I can't advise on the voltage and current specs for that.

[Robin Searle]

Just wire the electric fan to a wire going both to and from the heated rear window switch on your dash board and when the fan switch is pulled out fan will circulate and the green light will illuminate,will go off when switch pushed in, this way no more leaving the fan running and flattening the battery.

Robin

[fool73]

Got it working how I wanted it in the end. Wired the bulb (led actually) between the red and blue on the thermometer side of the relay. The red has a permanent 12 volts, and the blue makes ground when the thermostat reaches temperature. I just need to calibrate it to kick in at 90/95 degrees now. (hopefully never).