yes it has 4 wires
summit97
Do you have access to a volt meter?
If you do, 1 wire should be ground, and 1 will have constant 12V. the other wire will have a switched 12V when the brake lever is actuated.
The constant 12V wire will go through a resistor to lower the voltage the Light or LED is getting so you end up with a dim tail light, and then when the brake lever is pulled you get a bright brake indication from the full 12V wire that bypasses the resistor.
The stock light had an 8ohm 10Watt resistor and that did not work right when I changed mine to LED.
I had to increase the resistor value ( and of course I did not wright it down, and I'm not going to rip it apart to find out, but I think it was around 150ohm).
the new resistor does not have to be high wattage because LED's current requirements are very low in comparison to a light.
Now, in regards to how you hook up your led bar.....Mine had 2 wires, so it was easy. 1 was ground and the other hooked up to either side of the resistor so I ended up with dim tail light and then bright brake light.
Your going to have to use a diode check function to find out what you have if you want to get it hooked up properly. My guess is, whoever installed it, did not no what they were doing.
