I was in the process of wiring Auxilary back up lights on my 78 bronco plow truck with auto tranny, and discovered that my nuetral safety switch is not hooked up (posted on that before) can't find the plug where it is supposed to go. My new question is: is there a way to rig the switch to be able to get the stock reverse lights working and trigger the auxilary lights? I have four wires coming off the NSS: Red/Blue x2 (manual shows for NSS) a Black/Red (manual shows backup light switch) and a White/Blue (which seems to be a mystery). I have located a connetor (that does not match the connector on the NSS) on the drivers side firewall and it's wires are Black/Red and White/Blue (The W/B has 12v power of the correct fuse). Can I run the WB to WB and the Black Red into the Black red going to the reverse lights? Does that sound like it would work (assuming the switch works)? I really would like reverse lights to trigger when I shift. This whole post barely makes sense to me I hope you are not all dumber from having read it! Travis

 

Based on the info here, I am wondering how your truck starts in ANY gear. The RED/BLUEs are the lines that (when they are connected via the switch) allow the power from the ignition switch to get to the start solenoid. Without the NSS connected to those two wires in the truck (where ever the two matching ones may be hiding) the truck should not start. Now it IS possible that those two RED/BLUE lines (the ones NOT attached to the NSS and "hiding") have been jumpered/spliced together. Since that couldn't be done with the backup light portion of the switch without leaving the backup lights on all the time, the other two "hiding" wires are NOT connected (where ever they are) and no power EVER gets to the back up lights.

The WHITE/BLUE is the power feed and the BLACK/RED is the wire that feeds the backup lamps themselves. To get the backup lamps to come on, touch the two wires together. Or just connect them to the NSS W/B-to-W/B and B/R-to-B/R and the backup light issue should be resolved.

You can probably even resolve the non-function NS portion of the switch by locating the splice-point or jumper wire that has been added to bypass the switch in the first place. Just need to find the RED/BLUE wires that have either been spliced directly together or spliced to another wire and jumpered together that way.

 

Thanks for the reply. Would you guess the NSS was bad and they bypassed it rather then replace it or???? I have a reciept for a tranny "rebuild" in 99 (previous owner) Would they have swapped it out with a different tranny (different NSS)?. I'll look around for a jumper for the NSS I'm sure its there this truck has had some severe hack wiring done and I'm slowly trying to sort it out. Thanks for all you input. Travis

 

Its possible that the tranny was swapped but the NSS wiring should remain consistant. My electrical info lists the RED/BLUE wire colors as the NS circuit through the entire production run of the big Bronco. The difference was only in what the NSS looked like and/or where it was located.

 

I have found the connector! It was located in the wire harness that comes from about the middle of the firewall and heads towards the battery and starter solenoid etc (it was very near the blower area). It has a bright red 12 ga jumper sticking out of it and they used crimp on bullet connectors squished the bullet part down to fit over the stock terminals! In my defense it was slightly covered and on the wrong side of the engine compartment! The catch is the harness from the NSS is no way near long enough to make it up there my plan now is to cut the connector from the NSS move it up into the engine compartment and run new wires and a connector down to the NSS and see if any of it works. Thanks for your help Greystreak TB

 

Cool, glad you were able to lacate it. Sounds like the PO really did a number on the electrical system. Good luck with it. Holler if anything else comes up.

 

Got most of it wired up this evening and it will only start in park. Not in neutral is that normal? It's taken about 10 hours to sort this all out for about a 30 min job.

 

Hmmm, nope, it should start in either neutral or park. That may be whats wrong with the NSS. Basically the NSS is a three-position switch. The positions change when moving through the top three gear selections... Park, Reverse, and Neutral. If you test the NSS without the rest of the wiring hooked up to it you can read continuity across the switch wires. When in Park or Neutral you should have continuity across the two RED/BLUE wires and NOT the other two wires. When in reverse you should have continuity across the other two wires and NOT the RED/BLUE ones.