Reverse Lights on in Neutral

[Kenobi77]

Title. For context: 1986 FM145 manual. Transmission was taken out for a rebuild but the reverse light sensor was not removed.

Lights come on in neutral but turn off in any gear (even reverse). The switch is fine and has tested out perfectly. The real kicker is that the issue persists even when the switch and socket are disconnected. Has anyone ever had the same issue and could point me on where to start looking in the wiring to save some time?

Bulb sockets are clear of water.

 

[Uncle Gump]

Did you pinch a harness putting the trans in?

Kinda sounds like it to me...





I have been wrong before though.

 

[Kenobi77]

Did you pinch a harness putting the trans in?

Kinda sounds like it to me...





I have been wrong before though.

No, all are clear of the transmission at the moment and were tied up during installation to be clear of anything.

 

[Uncle Gump]

Well... somehow the fused battery wire is shorted to the back up lamp wire somewhere.

Inspect the connector closely... I mean... if they light up when disconnected... what else could it be?

Again... I've been wrong before.

 

[4x4junkie]

I'm not familiar with the FM-145 enough to know... Does it have a Neutral switch? (or a port for one?)
It sounds like the reverse lights are hooked onto the Neutral switch here rather than the Reverse light switch.

 

[SenorNoob]

The FM-146 in my truck had both. It wouldn't have been hard to get them (Or the wiring) mixed up. IIRC they are the same switch except for color of the plastic.

 

[Uncle Gump]

Well that makes sense. But... the EVTM says neutral switch is only on a 2.3L. Honestly though... I've seen other issues with wrong info published in this book. There is a top gear switch... but that wouldn't fit the symptoms as good.

@Kenobi77

@4x4junkie Added some good info that just might explain this.