Tail Lights Stopped Working

[Mac B]

So far I have checked the fuse and it is good.  Used a test light on both ends of the tail light fuse and it has current.  Disconnected the main plug at the left side of the trunk and tested it.  All wires have juice except the light and dark brown ones.  So, I have a problem somewhere between the fuse box and the trunk.  Could it be a bad headlight switch?

[Mac B]

I installed a new headlight switch. Still no tail lights.  It seems like it has to be between the switch and the plug in the trunk.

[bertfam]

Mac, do you have the two rear side marker lights? They come off the same circuit. It sounds to me like you may have a bad connection.

Check to see if these lights work or don't work:

1. Left and right blinker
2. Brake lights
3. License light
4. Parking lights (rear)

Ed

[Mac B]

Thanks Ed, brake lights, stoplights and back up lights work. Rear parking, marker,Iicense plate
and tail lights do not.  All front lights operate.



 

[bertfam]

Ok, that narrows it down a bit. You may have a bad ground, a bad connection at the Fisher Body connector or a bad splice connection where all the brown wires come together. Take a look at UPC 12, Sheet D4 below. I've pointed to the connector and the junction where all the brown wires come together. These are where you need to start looking.

Ed

[Mac B]

Thanks Ed, will follow your advice.  Fixing those lights is my task for today.  I trailered the car from the Camaro Nationals to Goodguys in Iowa, to Goodguys in Columbus and then back home to Texas.  Something could have come loose with all that travel. All lights were working in Maryland because the car passed Legends tech with no problems. The other thing I did not check were the brown wires going INTO the headlight switch plug.  I will test them with my test light as well.  I am going to keep at it and let you know what happens.

[Mac B]

Okay Ed, I checked the brown wire in the female terminal of the plug that attaches to the headlight switch and it is live with the switch on.  When I check the plug (Fisher Body Connector?) on the driver's side of the trunk there is no juice to the brown wire.  So...Doesn't it have to be between the trunk connection and the plug where the body harness connects in the front of the car?  Is that plug in the driver's side kick panel?  Thanks again for your help.

[bertfam]

Looks like you found the problem. I believe the plug is in the drivers side kick panel, but I don't have a 69 so I can't be sure. Maybe someone with a 69 can chime in.

Ed

[Mac B]

Here is the latest.  No juice from brown wire on the body side of the Fisher Body Connector.  I have a lawn mower battery that I use for testing.  When I separate the tail light harness  from the body connector and hook the tail light's brown wire terminal to the positive side of the battery and the negative side of the battery to the ground screw in the trunk I get no tail lights.  What am I doing wrong?  I would think I could get the tail lights to work by using an independent power source.

[bertfam]

It should. I think you'll have to start at the bulb(s) and work your way forward.

Ed

[69pace]

Here is the latest.  No juice from brown wire on the body side of the Fisher Body Connector.  I have a lawn mower battery that I use for testing.  When I separate the tail light harness  from the body connector and hook the tail light's brown wire terminal to the positive side of the battery and the negative side of the battery to the ground screw in the trunk I get no tail lights.  What am I doing wrong?  I would think I could get the tail lights to work by using an independent power source.

If you have double checked the grounds I would first check that the bulb is okay. If the bulb works someplace else look at the socket. Lastly I would use a meter and see if the brown wire passes a continuity check it may be broken inside the insulation somewhere down the line

[tom]

Could also have a short due to worn insulation on a wire. I use a seat belt warning buzzer to check for electric power, instead of a test light. I pirated it from a past car before it went to the bone yard. Add some wire and gator clips, you can hear if you have power. I would start at the lights, and see if you get power at the bulb sockets, if not follow trace the wire back and keep checking till you have power. I doubt there is a problem with the ground if the other lights are working. It has to be in that circuit someplace.

[Mac B]

Thanks for the help guys.  I really appreciate it.  I am going to use my independent power source today by disconnecting the ground to the rear light harness and connecting it to the negative battery post and connecting the brown wire in the harness to the positive post.  If the tail lights do not light up, I gotta have a short in the harness somewhere.

[Mac B]

Ok, rear harness works great with all lights functioning if I use an independent power source.  Sanded some paint off underneath the ground and that did it.  Now I have to dig into the wiring between the dash and the trunk because the tail lights doe not work when plugged in.  Replacing that harness looks like I have to pull the driver's side kick panel to begin.  What about the seats?  What else do I need to know to get at the harness that goes between the dash and the trunk?  Thank You

[69pace]

you can try a little dielectric grease in the connector such as used in the bulkhead connector, it would tighten up any loose connectors in the connector.