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.

 

[Uncle Gump]

@Kenobi77

Sure would be nice if you posted a follow-up with this thread.

What was problem?

 

[Kenobi77]

@Uncle Gump So sorry, have a terrible habit of leaving my threads to die with prep for college and work along with other things with my Ranger.

@SenorNoob is correct. Not too long after I started this thread I finally had the “duh” moment that the lights were an indicator the safety switch’s circuit was being completed. I got down there and tried to switch the connectors, which didn’t work at first, but finally was able to get it. The male for the lights fits more easily into the NSS’s socket than it does the reverse switch’s. I had to use so much force and distort the angle so much I’m surprised it didn’t break (yes, I checked, it was 100% clear of any dirt, grease, or debris).

It’s a very simple mistake, but the fitment issue is enough to make it not seem like one. It had been too long and I hadn’t labeled them; both of mine are the same color. Best to make notes from now on.

Correct, the manual is wrong. FM145 has the NSS on top of the transmission right in front of the shifter. This is a crop of the best picture I have of it from around when I first got it.