Can my rear marker lights be wired to work with the turn signals on 1970 Cutlass Supreme? I have a later model harness on the front and they blink with the signals.

 

Yes they can but you'll have to change the sockets to a dual filament bulb and tap off the taillights. With the added load, you may need a different signal stat.

 

There is a "gotcha" in this. The 1971-72 cars had the front side marker lights wired to flash with the turn signals. Those lights have one wire connected to the parking light circuit and the other connected to the turn signal circuit. When the park lights are off, the side markers flash in sync with the turn signals, as the ground is through the park light circuit. When the park lights are on, the side markers flash out of sync with the turn signals since the turn signal being on turns the marker light off. The reason why Olds didn't do this at the back is because the brake lights use the turn signal filaments. While you could wire the rear markers just like the fronts on the 71-72 cars, when you step on the brake pedal the marker would be on if the park lights are off and off if the park lights are on. When not on the brakes, they would work the same as the fronts.

 

OK that makes sense. I have an LED bulb in the front marker lights and every time I use the blinker with the park lights on it apparently switches which side is grounding the bulb so I have to reverse the bulb to make it work again. Do they make a led bulb that is not positive/negative specific that will work this way?

 

All diodes (Light Emitting Diodes), are inherently polarity specific. Joe, didn't take into consideration the brake lights. What about tapping off the front markers and running new wires to the rear?

 

The T10 bulbs I have are definitely polarity specific. I have even used jumpers on them and they only work 1 way.

 

Sorry , I edited my post above because you misunderstood. All diodes are polarity specific.