My friend installed my strobe lights yesterday, and today when I went to drive my car, the Engine Coolant light came on. The manual says this means the engine is overheating and that the levels should be checked (levels are fine) and the fan should be checked to see if it's running. I dont have any idea where the fan is LOL. But yeah... anyone ever had an issue like this...?? Not sure why suddenly the car would "overheat". Especially since the light comes on AS SOON as you start the car, and it sat all night. There's no possible way its overheated.... :?
Sounds to me like your friend tapped into the wrong wire. Completely disconnect the strobes and see if the problem remains.