On the inside of the bulkhead connector, see if you have wires terminating in cavities C & D. Wires are labled B1 and B2, that are 18 gage white and violet. If so, then that can be used the back up switch. You may have to make your own three wire harness. The three prong connector plugs are available with pigtails. There's two different types. I forgett the difference, but you can see it in how they mate.So my column is from a 1969,and the tranny 727 is from an 85 d150, so I guess I'm gonna have to rewire the back up switch