[Jim Smolka]

In your '75, the wiring for the fog light switch should be there from the factory. Look in your trunk. All you have to do is connect the stock fog light switch. However, the fog light switch is designed only for low beam operation. I think you can simply move a wire in the dash to get them to work off high beam (this may be illegal in some states). Check out a Haynes manual, they have a good wiring diagram for the '75

If you install H4s, you propably need an additional wiring system to handle the load. I would use an aux relay system with a fused hot wire comming from the battery to power the lights. The relay would be mounted near the head lights and be triggered from the old power wire comming from the switch/stock relay to the head lights.

If your car does not have fog lights in it all ready, the steel part of the front bumper may not have the mounting bracket for the lights. If you need the front bumper designed for the fog lights, I have an extra one.