reverse tail lights don't work

[Ecomike]

Other than bad bulbs, or a bad NSS, is there any other possible cause for the reverse tail lights to not work? I have read older threads already about the NSS issues and repairs, and it is next on my list, unless some one comes up with something easier to check first that I might have missed. I could not find a reverse light fuse, and the brake and rear running lights work.

It is an 87 Wagoneer, XJ, 4x4, 4.0, with AW4.

Thanks.

 

[Shorty]

it's been a while, but I think the "trans" fuse in the fuse block also powers the reverse lamps. Hit your "power/comfort" switch and see if it's got power to the light. Both of these are on the same circuit, IIRC.

 

[joe_peters]

it's been a while, but I think the "trans" fuse in the fuse block also powers the reverse lamps. Hit your "power/comfort" switch and see if it's got power to the light. Both of these are on the same circuit, IIRC.

I think Shorty has it right.

 

[DrRandy]

My vote is the NSS, it was on my '91. Wiggle the shifter a bit and see if they work then. If so....NSS, easy fix, sux geting to it a bit. More-so when muddy!

 

[birchlakeXJ]

The neutral safety switch can oftentimes (not always) be disassembled, cleaned, regreased and reassembled to restore function.

And the NSS is definitely a common cause of not having backup lights.

 

[ParadiseXJ]

If you can start in P and N, but your lights don't work...it's the fuse...like Shorty and joe_ say.

I have a short somewhere in my Power/Comfort or my lights that keeps blowing the fuse. Haven't pinned it down yet.

 

[winterbeater]

Seems like the starting contacts could be good, but the back up lights ones may need cleaning. Jumping the plug with a paper clip or piece of wire would tell you.

 

[heyhar]

Ecomike, you're usually the one answering these kinds of questions!
Like suggested, jiggle the shifter through the whole 'R" detent, see if they'll flash. That's what my '92 needs. The night it turned 200k, my son and I had it at the vo-tec, taking a night class for body shop. As I was backing it into the garage, they magically lit up. Hadn't worked for years! And haven't worked much since. But, if I hold the shifter between Park and Reverse, with tranny in Reverse, they'll usually come on. Time to head to Harry's and get one, clean it, swap it, repeat...

 

[sjx40250]

My backups didn't work for years but I didn't have the problem with starting. NSS clean fixed it. 87 is long over due for NSS maint! I have a 98 that needs it!

 

[FlexdXJ]

If you can start in P and N, but your lights don't work...it's the fuse...like Shorty and joe_ say.

I started mine in park and neutral for months and it was my NSS. :dunno:

 

[Ecomike]

Great feedback guys! Thanks! The NSS was replaced with an ebay rebuilt unit about 5 years ago. No starting problems with it. But I do have some custom wiring, a power switch to the TCU memory power wire, and another toggle switched hot wire for TC lock up, unlock to the TCU, that I might have tripped off by accident. Will check it and the fuse next for sure! If that is not it, I will bite the bullet and pull the NSS. Oh, and already tried wiggling the shifter and going back and forth to see if there was any sign of a back up light life, got nothing.

 

[Shorty]

Other than bad bulbs, or a bad NSS, is there any other possible cause for the reverse tail lights to not work? I have read older threads already about the NSS issues and repairs, and it is next on my list, unless some one comes up with something easier to check first that I might have missed.

nobody's doubting the possibility of a bad NSS-- I think Ecomike is just looking for other causes and things to check-- I tend to agree that an '87 without NSS service is pushing the envelope, but he's already planning that part

 

[MJmk]

I have a short somewhere in my Power/Comfort or my lights that keeps blowing the fuse. Haven't pinned it down yet.

Not sure if the previous owner did it, or it came from the factory, but mine had one of the wires to power/comfort switch pinched between the wedge and nut that holds the steering column up to the dash. Kept blowing the "trans" fuse, causing no b/u lights.

 

[MJmk]

Great feedback guys! Thanks! The NSS was replaced with an ebay rebuilt unit about 5 years ago. No starting problems with it. But I do have some custom wiring, a power switch to the TCU memory power wire, and another toggle switched hot wire for TC lock up, unlock to the TCU, that I might have tripped off by accident. Will check it and the fuse next for sure! If that is not it, I will bite the bullet and pull the NSS. Oh, and already tried wiggling the shifter and going back and forth to see if there was any sign of a back up light life, got nothing.

Easy test with a meter before changing out the switch. Just unplug the switch from the harness under the hood, clip your meter leads to "A" and "E" as marked on the connector, put the meter where you can see it from inside the Jeep, get in, unlock the wheel and shift to reverse. Got continuity?
Double check me on the "A" and "E", I believe that is correct, but i'm getting old :looney:

 

[winterbeater]

Or jump between the leads in the plug to see if the back-ups light up.