Paul Bruchal Posted January 31, 2016 Share Posted January 31, 2016 I have no back up lights. I cut the wire and traced it. Found it spliced from 1 to 2 back into 1 wire again for no reason and still, i couldnt find voltage. Anyone have any idea why both tail lights are out at the same time??? Link to comment Share on other sites More sharing options...
Gene Posted January 31, 2016 Share Posted January 31, 2016 Start with the fuse panel. Ignition on, check for voltage at both sides of 7.5 amp "trans" fuse. If power at both sides of fuse, then check reverse light switch. If not that, then something in the wiring itself. Good luck! Gene Link to comment Share on other sites More sharing options...
87MJTIM Posted January 31, 2016 Share Posted January 31, 2016 I'd start with the trans switch first. Test it to see if it works. Don't know what trans you have, but the switch is my first guess. Link to comment Share on other sites More sharing options...
Paul Bruchal Posted January 31, 2016 Author Share Posted January 31, 2016 I have a manual trans. Soo, check the trans fuse & backup light switch on the transmission. Link to comment Share on other sites More sharing options...
cruiser54 Posted January 31, 2016 Share Posted January 31, 2016 Fuse first. Link to comment Share on other sites More sharing options...
Paul Bruchal Posted February 1, 2016 Author Share Posted February 1, 2016 The fuse is not blown. I checked the trans and I think i found the switch. Is it on the driver side or the trans with a rubber boot and plastic wire tube coming out of it? Kinda small? Link to comment Share on other sites More sharing options...
87MJTIM Posted February 1, 2016 Share Posted February 1, 2016 Do you have an AX4 or 5 (2.5) or a BA10 (4.0)? The BA has this for its switch http://www.rockauto.com/catalog/moreinfo.php?pk=939441&cc=1181483&jnid=478&jpid=0 The AX has this switch http://www.rockauto.com/catalog/moreinfo.php?pk=932883&cc=1181472&jnid=444&jpid=0 Link to comment Share on other sites More sharing options...
Pete M Posted February 1, 2016 Share Posted February 1, 2016 if the switch works and you have power at the switch, then it is possible that the power is stopping at the rear harness connector located behind the drivers side rear tire. that connector killed my brake lights once and I found it so horribly rotted that I had to cut it out and replace it. :( Link to comment Share on other sites More sharing options...
Paul Bruchal Posted February 1, 2016 Author Share Posted February 1, 2016 Do you have an AX4 or 5 (2.5) or a BA10 (4.0)? The BA has this for its switch http://www.rockauto.com/catalog/moreinfo.php?pk=939441&cc=1181483&jnid=478&jpid=0 The AX has this switch http://www.rockauto.com/catalog/moreinfo.php?pk=932883&cc=1181472&jnid=444&jpid=0 I have a 1988 Pioneer LWB 4.0 5 speed 4x4. I don't know which trans I have. Ill look more at this switch after work today. Thanks for those links! Link to comment Share on other sites More sharing options...
Paul Bruchal Posted February 1, 2016 Author Share Posted February 1, 2016 if the switch works and you have power at the switch, then it is possible that the power is stopping at the rear harness connector located behind the drivers side rear tire. that connector killed my brake lights once and I found it so horribly rotted that I had to cut it out and replace it. :( I unplugged that connector and it looks pretty corroded. Ill try to find another at autozone Link to comment Share on other sites More sharing options...
87MJTIM Posted February 1, 2016 Share Posted February 1, 2016 Do you have an AX4 or 5 (2.5) or a BA10 (4.0)? The BA has this for its switch http://www.rockauto.com/catalog/moreinfo.php?pk=939441&cc=1181483&jnid=478&jpid=0 The AX has this switch http://www.rockauto.com/catalog/moreinfo.php?pk=932883&cc=1181472&jnid=444&jpid=0 I have a 1988 Pioneer LWB 4.0 5 speed 4x4. I don't know which trans I have. Ill look more at this switch after work today. Thanks for those links! A stock trans is BA10/5 I finally broke down and replaced my switch just before I swapped trans to an AX15. :doh: Link to comment Share on other sites More sharing options...
Paul Bruchal Posted February 2, 2016 Author Share Posted February 2, 2016 is this it? Link to comment Share on other sites More sharing options...
87MJTIM Posted February 2, 2016 Share Posted February 2, 2016 That is the BA10 back up light switch. Link to comment Share on other sites More sharing options...
Paul Bruchal Posted February 2, 2016 Author Share Posted February 2, 2016 Sweet, So check for voltage when ign. is on and its in reverse. If no voltage, replace becuse the fuse it still good. Link to comment Share on other sites More sharing options...
cruiser54 Posted February 2, 2016 Share Posted February 2, 2016 Or, with the key on, unplug the harness from the switch and jumper across the harness terminals. Link to comment Share on other sites More sharing options...
87MJTIM Posted February 2, 2016 Share Posted February 2, 2016 One wire s/b Blk/ Yel. This is the feed wire. With ign in run, it will show voltage. The 2nd wire is Brw/Wht. This feeds pwr to the lights. When you put the trans in rev, the switch closes the circuit. Turn ign to run, but don't start engine. Check that you have pwr coming in on the Blk/Yel. Put the trans in rev. see if you have pwr on the Brw/Wht. If not, then replace switch. Link to comment Share on other sites More sharing options...
Rohls Posted March 7, 2016 Share Posted March 7, 2016 So on my AX15 92 MJ 4.0 I have no reverse lights. They suddenly stopped working. What is the fuse labeled as? I have no TRANS fuse... Link to comment Share on other sites More sharing options...
Paul Bruchal Posted March 13, 2016 Author Share Posted March 13, 2016 I had my Jeep towed to a garage to have alot of things done to pass my "military POV inspection". The garage i brought it to did everything on the list except the reverse lights. They don't specialize "in internal engine or transmission" and they "thought" it was the rod that pushes the reverse light switch wore out and thats why there was no voltage. They drove my jeep down the block to a transmission shop for me. 2 weeks later once i got out of the field, training, the trans. garage said it was the switch that was bad. It took awhile but in just glad its finally done. Link to comment Share on other sites More sharing options...
LilWilly Posted March 26, 2016 Share Posted March 26, 2016 Is there a different switch for the automatic transmission? I'm having the same issue. Link to comment Share on other sites More sharing options...
gogmorgo Posted March 27, 2016 Share Posted March 27, 2016 The AW4 uses the neutral safety switch to trigger the reverse lights. It probably just needs cleaned out. If you've been having the odd no-crank this is also likely the culprit for that as well. There are a few good write-ups out there, google's your friend. There's a great one on bc4x4 I think it is. Link to comment Share on other sites More sharing options...
LilWilly Posted March 30, 2016 Share Posted March 30, 2016 The AW4 uses the neutral safety switch to trigger the reverse lights. It probably just needs cleaned out. If you've been having the odd no-crank this is also likely the culprit for that as well. There are a few good write-ups out there, google's your friend. There's a great one on bc4x4 I think it is. Thanks. I had been trying to figure out which Trans it had, but can barely keep it parked long enough to sort anything out. looking forward to getting into Criuser54's top 5 in hopes of sorting a lot out. Link to comment Share on other sites More sharing options...
gogmorgo Posted March 31, 2016 Share Posted March 31, 2016 http://bc4x4.com/tech/2010/jeep-neutral-safety-switch-nss/ That's the link to the write-up I followed when I did mine a couple years ago. Before putting mine back together after packing it full of dielectric grease, I ran a bead of silicon around the edge to keep it sealed a bit better. In MJ/XJ's the automatic behind the 4.0 was always an AW4. There were some differences over the years, though, although they mostly coincide with major vehicle updates, i.e. Renix to OBD1 to OBD2, with some minor differences between those years. But the NSS cleaning applies to all of them. It's also quite economical to clean the NSS instead of replacing it. 99.9% of the time that's all it needs, and they're usually around $200 to replace. Link to comment Share on other sites More sharing options...
Minuit Posted March 31, 2016 Share Posted March 31, 2016 As a general rule, any time the reverse lights don't work in an AW4 equipped Jeep, the first thing you should do is clean the NSS. I've maybe heard of 2 occasions EVER where the NSS was actually bad. When I took mine off it had a lot of crud in it. A cleaning and some dielectric grease later and my reverse lights work perfectly. Takes about 2 hours tops to do the entire thing. Just don't lose the tiny little contacts and springs it has inside. Link to comment Share on other sites More sharing options...
gogmorgo Posted March 31, 2016 Share Posted March 31, 2016 As a general rule, any time the reverse lights don't work in an AW4 equipped Jeep, the first thing you should do is clean the NSS. After you've ascertained the bulbs aren't just burnt out... Link to comment Share on other sites More sharing options...
Minuit Posted March 31, 2016 Share Posted March 31, 2016 Kind of hoped that didn't really need to be said... Link to comment Share on other sites More sharing options...
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