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1968 4 speed reverse light wiring dilemma

91r/t

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Ok so here goes. Got the wiring kit from Megaparts with the Violet wire and the black wire with the jumper for the light in the dash. I have (2) 68 Mopars (Charger and Runner) here I am trying to wire in the reverse lights. Both cars are missing the harness completely. Everyone is saying use port Z in the bulkhead for the wire to go to the reverse light on the dash as does the instructions included. I am working on the 68 Roadrunner at the moment. Both cars use port Z for the left hand front marker/turn signal light according to the Wiring diagram for 68 and the cars themselves. Dark Green wire with a white tracer. So that wont work to use that port for that light. Also, they want me to plug the two wires into ports C & D on the wiper bulkhead on the top plug, but looking into the inside of the car, there is nothing in there on those two plugs to get power from on either car. The only thing shown in the wiring diagram for 68 that goes into those is the auto tranny backup switch if its an auto, so what the hell is plugging it into that going to do for me for juice? This thing is driving me nuts. Why is the 68 so different from all the pics I am seeing of 69's and up? Am I missing something? Someone chime in if they can help solve the reasoning why its so different?
 
Now looking closer I see the radio white wire is supposed to be spliced into/running into port D in he car, but I have nothing plugged into that port in the car. I need to find the violet wire going to the back of the car from the instrument panel harness, and plug that into port C inside the car. So the radio wire would give me power, and the violet wire would send the current back to the reverse lights. I am still stumped on the port Z thing for the light in the dash. There's no way that's correct because both cars have the left turn signal/marker lamp wire there. I could just use an open port in the wiper plug like A or B and run it into the car that way so the light works.
 
Here are a couple of pics from a 69 service manual. I would think 68 would be the same. Dash lamp wire goes to Z in bulkhead under dash. The other side is your harness that goes down to the back up lamp switch on the tranny.

20190328_162852.jpg 20190328_163501.jpg 20190328_163802.jpg
 
68 is definitely not the same. The Z port shows dark green for left turn. I have a 68 manual in front of me. I converted the one to a 4 speed and it has an auto plug in it with violet and white but nothing goes to the bulk head. Neither car does in fact. I’m beginning to say f*^% reverse lights!
 
Here are a couple of pics from a 69 service manual. I would think 68 would be the same. Dash lamp wire goes to Z in bulkhead under dash. The other side is your harness that goes down to the back up lamp switch on the tranny.

Its almost like they didn’t plan the light out for interior because it was a half year deal and then switched **** around in 69.
 
I guess that is why '68's didn't have a dash reverse light ! Your actual reverse lights though are wired through D and C the same as '69.

Wire up the A or B to the dash reverse light... and call it done.
 
I guess that is why '68's didn't have a dash reverse light ! Your actual reverse lights though are wired through D and C the same as '69.

Wire up the A or B to the dash reverse light... and call it done.

My problem is I have no violet or white wire going to the C or D bulkhead on the inside of the car on either car. It’s almost like it’s missing that portion of harness so when you plug the reverse switch lights into the bulkhead under the engine bay there’s nothing on the other end to power them.
 
Didnt Cranium go through this a while back? Thought he added a light to one of his 68 Chargers. I may be mistaken though. Send him a pm.
 
Looking at the '68 wiring diagram.. it appears they took the wires directly from the door A pillar connector to the trans switch. White wire is feed... violet out of the switch to reverse lights. dotted lines shown to the firewall bulkhead D and C for both.. so I bet Auto's went the way the wiring diagram shows and manuals got the extra wires shown as dotted... You switching from Auto to manual in both cars??
 
Nope the runner yes. The charger has a new harness and I think it was replaced with an auto type when it was done because my buddy didn’t know any better. I found both auto style plugs about 5 minutes ago so I can send them into the bulkhead. Holy **** this under dash work sucks! :D
 
Made a jumper to confirm my thoughts....F you cars I win! Thanks for all the advice it helped me mentally as well!
:thumbsup:

69D79A5B-2A4F-4A69-B30B-AE9A64971485.jpeg
 
My '68 was bought with the entire reverse light harness missing from the car, from plug end to pigtails
for some reason.
I just hard-wired them myself instead. Simple circuit, really.
Yes, I have the itch to install the little amber dash light now too, which will be easy - just include it in the
already fabbed circuit.
 
My '68 was bought with the entire reverse light harness missing from the car, from plug end to pigtails
for some reason.
I just hard-wired them myself instead. Simple circuit, really.
Yes, I have the itch to install the little amber dash light now too, which will be easy - just include it in the
already fabbed circuit.

Yup seems like everyone just said screw it and ripped it out for some reason. :rolleyes:
 
These are the purple and white wires in the harness I found wrapped up under tape. I think this pigtail is on all harnesses that are aftermarket, and if its a 4 speed then you pop the end off the leads and stick them into the bulkhead in C & D ports. I think they go to the neutral safety switch maybe on an auto car? Anyone can comment if I am wrong but that's where I found the wires taped up. I will make these work and then have reverse lights again on both cars!

upload_2019-3-29_8-52-3.png
 
Looking at the '68 wiring diagram.. it appears they took the wires directly from the door A pillar connector to the trans switch. White wire is feed... violet out of the switch to reverse lights. dotted lines shown to the firewall bulkhead D and C for both.. so I bet Auto's went the way the wiring diagram shows and manuals got the extra wires shown as dotted... You switching from Auto to manual in both cars??

You are correct. I took the female terminals out of that plastic plug shown in the picture above and then I undid the bulkhead from the firewall and dropped it down into the car. I was able to insert the female terminals into ports C&D on the bulkhead and then reinstall the bulkhead in the firewall. It took about 15 minutes so I’ll do the same on the road runner tomorrow and all will be fine. Thanks again!

:thumbsup:
 
You are correct. I took the female terminals out of that plastic plug shown in the picture above and then I undid the bulkhead from the firewall and dropped it down into the car. I was able to insert the female terminals into ports C&D on the bulkhead and then reinstall the bulkhead in the firewall. It took about 15 minutes so I’ll do the same on the road runner tomorrow and all will be fine. Thanks again!

:thumbsup:


Agreed, it depends where you reverse light switch is. On AT column shift setup the reverse switch is on the column and as you pictured that would be appropriate. Stick the connectors in C & D and the wires then route down to the tranny located reverse switch on a 4 speed and I believe also for a floor shift AT. I don't know all the specific details but IIRC 4 speeds have 2 wires down to the tranny for reverse and on some or all AT there are 4 wires down to a switch that handles neutral safety and reverse.
 
Agreed, it depends where you reverse light switch is. On AT column shift setup the reverse switch is on the column and as you pictured that would be appropriate. Stick the connectors in C & D and the wires then route down to the tranny located reverse switch on a 4 speed and I believe also for a floor shift AT. I don't know all the specific details but IIRC 4 speeds have 2 wires down to the tranny for reverse and on some or all AT there are 4 wires down to a switch that handles neutral safety and reverse.

Yea I knew the circuit and how its wired, it was more of a specific 68 thing, why my Z port was not empty, and then where the violet and white reverse lights were hiding.

:thumbsup:
 
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