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70 Charger 500 - dash removal and wiring question

Triplegreen500

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So, the previous owner wired in a dixie horn setup with some....hillbilly-level wiring (and I'll leave it at that). I've downloaded and printed out the wiring diagram, and I've done quite a bit of wiring in my life so I have no problem reading it...but I'll be damned if I can find what these wires are. And I'm going crosseyed, so I figured I'd ask the pros.

There's a small bundle, under the dash, in the area of the parking brake release. This is what they hacked into for their horn relay and its own pushbutton under the dash. I have:

black with a red tracer
dark blue with a yellow (maybe light green - it's pretty filthy) tracer
light green
light green
and, spliced together into a factory rubber splice with what looks like a ground-screw loop, a pair of dark blue with white tracers (these are heavier gauge than the others).

The diagram shows a horn relay that should have:

2x black with tracer (but what color? the diagram just says "black-tr")
dark green with red tracer

Where, physically, is the horn relay supposed to be? Did they hack into what used to be the horn relay?

Other electrical issues I'm trying to solve are, no gauge lights (headlights, taillights, high beams, and turn signals all work outside the car, but no gauge lights).

Right turn indicator on the dash does not work (left, and high beam, indicators do work)

Things that DO work:
Key buzzer
both door switches
dome light
console light-package lights
glove box light
horns themselves (I unbolted them and fed them voltage on their own, and they do honk)

I didn't want to go hooking those blue/white trace wires to ground if they're supposed to be hot...but damned if they don't show signs of a bolt through the ring.

Are the light greens supposed to be connected to each other as well? They're not yellow - they look like hi-viz construction vest color. I also see some other wires that are yellow, so I think these are going to be called out as light green. I could be wrong.

I'll keep poring over the diagram, but the next question is...how the HELL do you get the cluster out? I have it loose, and can almost get it out, but the bottom right corner gets caught on the a/c vent surround. Does the knee bolster piece need to come off? Or do I just keep wiggling the left side out at an angle, hoping there's enough wiring slack? How do you get that knee bolster off the dash skeleton? Clips? I didn't feel any nuts on the backside... I've lowered the column so it's out of the way, but I want the gauges out so a) I can test switches, dimmers, bulbs, and voltages, and b) so I can have access to stuff and look around better.

Thank you for any pointers - I've had the car 2 weeks and I'm trying to keep making progress so it can hit the shows in '21....and so I can drive it and enjoy it!! Right now, though, I'm going to take some ibuprofen for my back spasms, and dig through that diagram some more.
 
You need to break down electrical questions to 1 or 2 questions per thread here! I can help but reading a list of problems gets me overwhelmed.
The horn relay is hidden behind the gauge panel.
Sometimes the dash lights don't work because the dimmer switch is bad or the wire plug to it is damaged or loose.
The cluster has several screws holding it to the dash frame. The master wire plug is a 5 or 6 pin connector shaped like a thin rectangle and has very little slack to it. I extended mine to make installation easier. The steering column needs to be lowered to get the cluster out.
 
The wire colors often correspond to similar functions elsewhere. As an example, MOST orange wires in the dash relate to lighting. Gauges, map light, ash tray, glove box, etc.
I have found that while the service manual wire diagrams are helpful, there are some wires shown that my untouched harness does NOT have and at the same time, I have wires that are NOT listed on any diagram that I have seen. There are subsections in the service manual that do cover other areas like heating and A/C where they show the wiring for those components.
 
Do it the safe way and prevent most of the electrical issues that all older car have, just get a new harness.
Wiring diagrams are in Section 8 of the FSM. If you don't have one yet, you need one and the downloads are free.

https://www.yearone.com/Product/chrysler-b-body/hu272b
https://www.yearone.com/Home/FreeShipping

Expensive upfront but cheaper than a dash fire or the time it takes to keep tracking down electrical problems.
"Quality is remembered long after the price is forgotten"
 
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The dash side harness can be REAL expensive.
 
I still need to figure out how to disassemble it...column is lowered, cluster is loose, I can get the outer (headlight switch end) end about 2" from the installed position, but the inner (wiper switch) end is getting caught behind the center a/c vent surround piece. Does it all need to somehow be unplugged in order to remove? This is an a/c car...there's like zero room up under there to reach up and around, but I guess I can start removing ducts and stuff if that's what has to be done.
 
Do it the safe way and prevent most of the electrical issues that all older car have, just get a new harness.
Wiring diagrams are in Section 8 of the FSM. If you don't have one yet, you need one and the downloads are free.

https://www.yearone.com/Product/chrysler-b-body/hu272b
https://www.yearone.com/Home/FreeShipping

Expensive upfront but cheaper than a dash fire or the time it takes to keep tracking down electrical problems.
"Quality is remembered long after the price is forgotten"

Typically sound advice, but you need to compare the functionality of the old harness to the new, not so much as colors but where they go and what they do. More than one M&H harness has been mis-wired from the factory. Not terribly common, but it happens and can introduce a new and/or different problem. I'd sort out what's there first.
 
It has been awhile since I pulled one that had never been out of a car before. There are metal straps to retain the bunches of wires, there various plastic plugs for the headlight switch, panel dimmer, wipers and gauge functions are all fairly short too. Asian or female hands would be a great benefit here!
 
My hope is, I'll figure out and repair the wires that they tapped into for the horn, and somehow the dash lights will come back online. Maybe they cut the wrong wire when they did that horn thing...but I usually don't get that lucky.

As for function, EVERYthing in the interior works other than gauge lights, and the horn. Oh, and the clock (surprise). I'd rather not disassemble any more than I need to, but if I need to...

I ordered a factory reprint wiring manual earlier tonight, depending on ship time with the holidays, I may see it before new years...
 
The plastic connectors and wire insulation is 50 years old and plastics get brittle with age. As for taking the dash apart, get a Factory Service Manual. It is much easier than you think. They assembled these cars very quickly as sub assemblies, the take down procedure is just the reverse.
Take your time and don't take shortcuts, it is never faster or better in the end.
 
The plastic is usually more brittle when the car is in the south with the heat. My 2 California cars had harnesses and connectors in excellent condition.
 
The harness is in fine condition, except where this meatball hacked it up. Can someone pull their horn relay into view and tell me what wires go into it, by chance?

Maybe my back spasms will have quit by next weekend and I can try to hit a junkyard to see what I can find...
 
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