67 Charger - Tailights not working

[Dean Prevolos]

The turn signal lights work, the brakes lights works but the taillights won't work with my light switch on at night. I have changed the headlight switch 3 times, with new switches. I am hearing the answer " IT'S THE GROUND WIRE". But how is it that my turn signals work and brake lights work but no tailights? My car is a 4 speed, if anyone needs to know that fact.

Any suggestions are appreciated. I've spent so much time on this I am resolved to driving in the daytime only, HELP.

 

[turbine68rt]

@Don Frelier

 

[Speedbird]

Yes. Not a ground issue since each bulb shares the ground.
Unless every bulb has a bad ground since you say none work and it's a very strange situation.
According to these prints I drew up when building one of these cars there is a resistance connection somewhere in that circuit.
The trunk area? That would be my guess since the circuits are separate and from what you say.
I pulled most of this from factory prints with my improvements to some unclear and unrelated front end things
Does your license plate lamp work? It's not fed through the resistance. The splice is probably OK.

 

[twecomm]

I have a 66 and looking at my shop manual schematics, I see some slight differences in the wiring between 67 and my 66. In both cases, the voltage for tail lights comes from terminal "B" on the headlamp switch. On my 66, it's a black wire, designated L-7 on the schematic and wire table. That wire goes to the connector for "body wiring". The other side of that connector it's still a black wire designated L-7.
I have a hard time seeing the numbers on the posted schematic when I zoom into it, but it appears that L-7 is the same wire designation for taillights inn both a 66 & 67.
That wire goes to a "common point " which is what they called a "welded joint" that joins (splices), then fans out to the sockets for each of the six tail lamps to supply + 12 V to the "tail light" filament of all 6 dual filament tail lamp bulbs. In the case of your 67 schematic, there is a "resistance" wire just prior to that common feed point in the path of wire L-7. Speedbird is correct.. Check your license plate light, as it's fed voltage prior to the resistance wire. if it works, your problem must be the "resistance wire" which is in the bundle of wiring between dash and trunk area. Not sure, but I believe that "Body Wiring" connector is in rear trunk area. Bad wire, bad connector pin/crimp or bad resistance wire, can't see what else it could possibly be if license plate light works.

 

[devinism]

B2 on the headlight switch is power in for the tail / park lamps. Make sure you have power there.
B1 is power in for headlights only.

Both should have power anytime the battery is connected.

 

[origcharger]

In my experience when electrical issues don’t make sense, it’s most often a problem with ground(s)

 

[RemCharger]

The resistance wire is inline with the harness in the trunk by the jack. See if there's power going to the resistance wire in

 

[twecomm]

It would be nice if you would post when you solved your problem and what that solution was.

 

[Dean Prevolos]

Good morning, today I am gong to tackle the rear tailight problem. My license plate light does not work. I know of the "bundle" of wires that are wrapped in tape and stuffed in the left rear quarter crevice under the spare tire. I will start there. I also am aware of the breaker in the driver kick panel and tested those wires for power, so you are all leading me to believe that the issue may be in that bundle of wires. I will get back to the Forum on what I find. I do have a manual and I have a color coded wiring diagram. My car is also a manual trans. I see that the Tail Light wire color is black which leads to the Resistance connection, which also has the license plate wire spliced into it. That black wire runs to the kick panel plug, location #3. Thank you all for your input, much appreciated.

 

[What’s up dock]

I had the same problem. I ran dedicated ground wires to each have of the tail light housings to be sure, because of the fresh paint. I do that on all cars anyway, but it turned out to be the resistance wire in the left side of the trunk.

 

[Dean Prevolos]

Yesterday I had no power at the resistance wire and it was not in good condition, so I changed it but the lights still did not work with the light switch on. I then removed the tape around the cluster of wires and found some bare wires, hard and dry ( see photo) , which I cut out about 12 inch section and replaced with new wires. Still nothing. The wires all connect to that breaker in the driver kick panel, which I replaced during my restoration. I think the wire for my tailights needs to be replaced all the way from the trunk to the kick panel. I didn't have time to check the B-2 terminal of the light switch. The headlights work just fine, so the B-1 wire has power. I have a show this Saturday so I will work on it next Sunday. Thanks to all for their input. I'm glad I have brake lights and turn signals.

 

[Dean Prevolos]

I had the same problem. I ran dedicated ground wires to each have of the tail light housings to be sure, because of the fresh paint. I do that on all cars anyway, but it turned out to be the resistance wire in the left side of the trunk.

I understand the fresh paint issue for grounds, well taken. Did you ground each Half of the tailights where the bolt fastens to the chassis inside the trunk? If you have a photo of that I'd be interested to see how you did that.

 

[Dean Prevolos]

B2 on the headlight switch is power in for the tail / park lamps. Make sure you have power there.
B1 is power in for headlights only.

Both should have power anytime the battery is connected.

I have no power on the B2 female plug that connects to the headlight switch.

 

[devinism]

I have no power on the B2 female plug that connects to the headlight switch.

There's the problem.
Now go to the fuse panel and check both sides of the "Tail" fuse. You may just need to use a small wire brush to cleanup the terminals?
If no power there then....... happy hunting.
If you see any splices in the dash harness remove them.

 

[67 Mopar]

Resistance Wire...

 

[Dean Prevolos]

There's the problem.
Now go to the fuse panel and check both sides of the "Tail" fuse. You may just need to use a small wire brush to cleanup the terminals?
If no power there then....... happy hunting.
If

Resistance Wire...
View attachment 1818327

you see any splices in the dash harness remove them.

 

[Dean Prevolos]

I had no power to either side of the fuse. You may recall I replaced a section of the the trunk tailight wires a few months ago because the wires were all bare under the tape and grounding out the tailights, so I thought. Before I started unraveling the entire run, I disconnected the resistance cable wire and ran a jumper wire from the plug of the trunk light to the female plug on the resistance wire and the tailights came on( see photo). It was the first time since I have owned the car that I saw what my tailights light up. So then I checked the power at the plug that connects the wires from the light switch to the plug in the driver footwell and I had no power. So I checked the plug going TO the light switch and still no power? So how does the light switch put the headlights on but not the tailights, with no power to the light switch? Anyway, I have a new light switch, so I replaced and still no taillights. So there is a pink wire (D3) that connects the headlight switch to the fuse panel. I checked the fuse panel, no power! So now I have to find out why. There is another pink wire (L8) that comes in from the block on the firewall and connects to the brake switch to light the brakes. Last year that was not working so I disconnected it and connected a pink wire, which had power, which is for the glovebox light ( which I don't have), so I connected that wire to my brake light switch and then I have brake lights. So I left that in place so my brake lights would work. Now I have to find what wire is not in the loop that connects the stop light switch, to the headlamp switch, to the fuse box to the footwell plug that provides electricity to the taillights! I will have to remove the front driver bucket seat so I can lay under the dash to figure this out. So thank you to all that have commented and a special thanks to Topher, 67 Mopar and devinism. P.S. I replaced the resistance wire and still have no taillights.

 

[chrger1967]

The turn signal lights work, the brakes lights works but the taillights won't work with my light switch on at night. I have changed the headlight switch 3 times, with new switches. I am hearing the answer " IT'S THE GROUND WIRE". But how is it that my turn signals work and brake lights work but no tailights? My car is a 4 speed, if anyone needs to know that fact.

Any suggestions are appreciated. I've spent so much time on this I am resolved to driving in the daytime only, HELP.

I was checking my lights last night and saw that my 4 ways are not working in the rear but work in the front. Everything else is fine, brake lights work, directionals and parking light. For some reason the rear 4 ways stopped working.

 

[chrger1967]

I had no power to either side of the fuse. You may recall I replaced a section of the the trunk tailight wires a few months ago because the wires were all bare under the tape and grounding out the tailights, so I thought. Before I started unraveling the entire run, I disconnected the resistance cable wire and ran a jumper wire from the plug of the trunk light to the female plug on the resistance wire and the tailights came on( see photo). It was the first time since I have owned the car that I saw what my tailights light up. So then I checked the power at the plug that connects the wires from the light switch to the plug in the driver footwell and I had no power. So I checked the plug going TO the light switch and still no power? So how does the light switch put the headlights on but not the tailights, with no power to the light switch? Anyway, I have a new light switch, so I replaced and still no taillights. So there is a pink wire (D3) that connects the headlight switch to the fuse panel. I checked the fuse panel, no power! So now I have to find out why. There is another pink wire (L8) that comes in from the block on the firewall and connects to the brake switch to light the brakes. Last year that was not working so I disconnected it and connected a pink wire, which had power, which is for the glovebox light ( which I don't have), so I connected that wire to my brake light switch and then I have brake lights. So I left that in place so my brake lights would work. Now I have to find what wire is not in the loop that connects the stop light switch, to the headlamp switch, to the fuse box to the footwell plug that provides electricity to the taillights! I will have to remove the front driver bucket seat so I can lay under the dash to figure this out. So thank you to all that have commented and a special thanks to Topher, 67 Mopar and devinism. P.S. I replaced the resistance wire and still have no taillights.

View attachment 1843423

I want to install some kind of trunk light; can you take a picture for me of where it hooks up to in the harness? I know the switch gets mounted on the tab on the left side, but where does the bulb mount? I'm thinking I could use a doorjamb switch with a Painless wiring light kit.