got brake and rear turn signals but no tail lights

67 CJ5, F134 all original.

I just removed a wiring harness the PO had installed when he towed the jeep. Neither b4 I removed it nor now do I have tail lights. I've got brake lights and turn signals but no tail lights. I plan on checking the tail light wire for continuity 1st and then the headlight switch itself.
Any other ideas on what I should check?
thanks, Bill

 

I'll trade you a front parking light for your passenger side brake light!

Haha, no seriously. I just finished installing a new harness on my '67 CJ6, and have everything working except rear passenger brake light, but I'm working on that. Anyway, I had to run the gambit on getting everything working and found that a lot of my issues involved bad ground. Are you working with a new harness, tail lights? If you have new tail lights check to see if they have the metal housing. If so you may have to scrap away the paint on the inside where the bulb fits. Was there any body work done to the jeep where the tail lights go? Any Bondo can interfere with having a good
ground. Are you using the original turn signal? There maybe some corrosion inside the housing and may need to be replaced.
Hopefully this may give you some new food for thought.

 

Sorry, never mind on the turn signal switch, since your not having any issues with that.

Good luck.

 

Do you have 1157 bulbs? Silly things I over look all the time.

 

Hard to give advice on electrical issues over the net ... you really need to be there and test the circuits yourself. Experience and insight of others doesn't help you much. I can tell you how to diagnose, but I likely won't be able to guess the problem from your description.

Do you have a multimeter? Do you have a copy of the factory wiring diagram? Pick the circuit you want to test and work backwards from there toward the battery. Turn on the lights and test the contact in the socket for voltage. No voltage? Move back toward the battery to the connector or plug or whatever. As mentioned above, the taillights use the 1157 dual-contact bulb - one brighter filament for brakes and directionals, and a dimmer filament for running lights.

Really, tracing out the problem with a meter or test light is the only sure way to fix something like this. Jumping around, testing first this component then that, may work, but it is not guaranteed to work, and you may end up more puzzled with nothing more to test. Follow the circuit back to its source, testing everywhere you can, till you isolate the problem.

 

thanks RJ'sCJ'6, Jmoto and timgr for ideas. Getting after it this morning with a mulitmeter and b&w wiring diagram. Do you know where I can get a color one (not that these wires will reflect the origianal anyhow!) but am still trying to find an original manual and wiring diagram on line.
the light fixtures do use 1157's....both elements are good but they are not the original and do have a separate bulb to the side of the 1157....could be my issue.

thanks guys...I'll report back !

 

What I used to do is photocopy-enlarge the diagram, then trace out the wires with colored pencil.

Maybe here? https://web.archive.org/web/20090802034217/http://www.earlycj5.com/technical/electrical/ - we used to have this stuff online in a technical library.

 

I ran into this problem once. In my case it turned out to be a corroded fuse.

 

If you have front running lights, it shouldn't be in the switch or the fuse. And the circuit to the rear tails is pretty basic.

 

What is known about your model jeep in it's original state is one thing. What is unknown about your jeep is what has been changed and/or added since new. That is why Timgr says the trouble-shooter has to have "hands on" the vehicle to repair it. Do you have the original type Light switch? If so, the first pull position turns on the front park lights only (factory wired) and the second pull turns "OFF" the front park and turns "ON" the tail/dash/head-lights. I find that a test light is much easier to use for this type of trouble shooting.

 

"If so, the first pull position turns on the front park lights only (factory wired) "

Only the front, without the tails?

 

Nope.. Take a good look at the diagram Tim linked to. The tail lights cannot come on with the first and second switch position unless you put a jumper on the light switch connecting two terminals on the switch and this was not done. The internal contacts on the switch will not allow this as said unless you install jumper.

 

Walt, I always bow to your experience and knowledge.

But I'm confused. The front and rear markers on my '56/'57 both light up together on the first pull-switch position, then on second position the front markers go out and the headlights come on. (There ain't no third position...) A replacement switch to be sure, but original style, with no external jumpers. It has dealer turn signals but no 4-ways.

If the tails don't come on with the first or second position, when do they come on?

 

PeteL and Glenn are correct that the front running lights and the tail lights do come on together. My test switch has a bad connection for the tail lights in the first pull position but is re-connected at the second pull by the factory jumper. I took the switch apart to visually check and can post a pic of the inside to show the contact layout if anyone needs it. Sorry for misleading y'all. Now I have to fix the one on my Tux as well because it acts the same as my test switch. I have a third one that will come apart before it goes into service.

 

Here is what the issue was......simplest thing. The aftermarket Peterson light fixtures use a tension spring type of socket. The two contacts (one low on the shaft and one halfway up) were not each making contact with the respective tensioner, therefore any power sent to the fixture was powering up the brighter turn/brake filament and nothing was going to the dimmer/tail light filament. Once I removed the bulb and reinstalled, listening for an audible click of both contacts...i had both tail lights and brake/turn signals! Thanks all for your help!