O.D. Switch Position Sensor

[TerminalSamurai]

I took a look at my tranny the other day, noticed both the Back-Up Lamp switch was disconnected (which I already figured since my lights weren't working), along with the O.D. switch. My question is, what does this sensor actually do when it's working.... since it's a manual transmission.

[Rayne]

Your 240sx must have had a manual transmission swap at some point.

The Over Drive(O.D.) sensor is for the automatic transmission and it turns on the O.D light, on the left side of the steering wheel, when O.D. is turned off.