Fuses? Haven't checked. Push the button for the heated windshield, and on comes the light! But it did that anyway. I'd agree that it should be hard to screw up the install, hopefully it is just a matter of the wires being connected and all is good, but I'm surprised that without a heated windshield in the car, the light did not indicate some sort of anomaly by flashing or something. Anyway, guess I'll wait for the right opportunity.