27. The reverse lockout solenoid can be hooked up or left disconnected. If left alone, it will be a bit harder to get the car into reverse since the solenoid won’t be able to do its thing. If you decide to connect it, less effort would be needed to get the shifter into the reverse spot. We decided to hook it up by wiring it into the brake light circuit. We wired it in parallel since wiring it up in series will cause the brake lights to be dim, and if the solenoid fails, so will the brake lights.