Originally Posted by fierosum
I want to know when the radiator electric fan is on. I added a small 1/8" diameter 14v bulb (looks like an LED) in parallel with the fan. See attached pic. Works great when the fan is on, the light is bright and does let me know when the fan relay kicks in at 195*F. But it illuminates about 80% when the car is moving and the temp is below 195*F. The fan acts as a generator and powers the bulb. So I added a 1N4004 diode in series with the bulb and the result was the same. I reversed the diode and the light would not come on at all. The engine is carburated not EFI. So fellas, I need someone with electrical knowledge to help me out here. Please and thank you in advance.
Feed the light power from a separate source and use the ground that gets pulled up from the relay to make the ground for the light.