After i turn off my car, the temp guage goes up about 15* but when i turn off my car and put on my lights for some reason the guage goes all the way past the 260* mark....I opened up the hood and its definately not 260. Does anyone know why this is??

 

The engine temperature should rise a little when you turn off the engine. When the engine is off the water pump stops spinning so the coolant doesnt flow anymore. It still has to absorb the heat from the engine so the temp will rise some.

The gauge going all the way up means the gauge wiring is shorting out or recieving power from somewhere it shouldnt be.

 

So is the temp really that high or not?

 

Probably not. If the temp only reads high with the headlights on make sure the gauge wires arent getting power from the headlight circuit.