Does anyone know where the Black/white stripe wire on the harness side of the NSS originates? If you want to know why I'm asking, read on...

I've had intermittent reverse lights since I picked this ['89 4.0L Auto 4WD] XJ up about a month ago. The fuse and bulbs were fine so I pulled the NSS last week and cleaned/rebuilt it but still no reverse lights. Because they were intermittent, someone here suggested a short so I started tracing today.

The reverse light wiring is good to the NSS plug, if I apply +12v to the brown/white stripe wire on the harness side (with the NSS unplugged) my reverse lights come on. I investigated the wires leading to the NSS from the harness and found that one of them [black/white stripe] is carrying voltage but only 4.93v. I have no idea where that supply wire originates but I suspect that only having 4.93v is the source of my reverse light issue. Any advice is greatly appreciated.

 

Have you tried unplugging both of those connectors at the trans dipstick tube area, one gray and one black? Spray them out with contact cleaner and reconnect. I've found corrosion in those before.

"trans" fuse in the fusebox is where the 12V originates, then goes through a blk/yel wire to NSS, via one of those connectors noted above..

 

Thanks Cruiser, I have cleaned both of the connectors (NSS and whatever the other multi-wire lighter color one is) with contact cleaner and given them both a coating of dielectric. The problem is that the wire (which is probably black/yellow but faded to look black/white) is only 4.93 at the back of the connector so the voltage drop is somewhere before the connector. I'll trace it from the trans fuse.

Thanks again.

 

Blk/Yel from "trans" fuse to the C115 connector "under dash to right of steering column". Then Blk/Yel to the connector we've discussed. After that, Yel to NSS.

 

You're a lifesaver, Cruiser. The C115 connector was disconnected. It must have been just barely pushed together (which was giving me the intermittent lights) and finally just came undone. Anyway, plugged it back in and I now have +12v at the NSS and reverse lights! You rock.

Thanks again.

 

I have the factory wiring diagnostics book next to my computer. It came with an 86 Comanche I bought a few years ago and it's been quite helpful. Glad you got everything working.