I connected a 12v led with resistor to the coolant fan relay. I scraped the edge of the relay socket and relay with an exacto knife, and drilled a hole in the top edge of the casing, to make room for the wire. The relay comes with 4 different numbers; 85 & 86 run a charge through the relay coil, 30 and 87 go to the device, in this case the fan.
Attaching the wire to #30 caused the light to come on immediately, showing that #30 was first inline and therefore the wrong one, because the light needs to be triggered by the temperature switch. I switched the wire to socket #87 and the light didn't go on, showing that #87 is correct, and only connects when stimulated to do so by the little coil in the relay.
Be sure to shove the relay to the bottom of the socket, to make sure it's connected. I routed this wire along the outside bottom edge of the frame with gorilla tape, with the light showing under the edge of the hood, outside of the window, and in a nice position to see from inside. I connected the other wire as a ground to the edge of the frame.
The light came with two 19.5 inch wires from luckybike on ebay for $2.95. Key words: Red LED Inline Resistor 12v Motorcycle Auto Diode Car.
Update:
The a/c fan caused the light to come on at 186 degrees. I removed a/c fuse #56, and the fan light came on at 206 at the peak of the hill.
The light turned back off at 204, and went back down to 190. The led light and temperature range of the fan are perfect for me now.
