Burnt connections

[ChallngeAccpted]

Hello everyone, so I just got under the dash so I could start pulling out my steering column as I am rust treating my floor, anyways I noticed a couple burnt connections. I looked at some wiring diagrams but I’m not quite sure how the second picture turns from black and brown wires into red? Also where does the red and orange wire from the column go to? I daily drive this car for several months until I decided to do a full resto and everything worked on the car. Should I replace the harness or what could have caused this? Thanks in advance!

 

[1973cuda]

This might help ,not sure its your problem?
Catalog

 

[ChallngeAccpted]

This might help ,not sure its your problem?
Catalog

The MAD bypass has not been performed on my car yet. I was planning on doing that very shortly however. To be honest, I do not know if that directly caused those to burn or not, but I would imagine that is likely to be the reason. On the diagrams in my Mopar, looks like the thick red wire is the one that burned in the first photo. That was soldered together by the PO. I don’t know about that other connection with only 2 red wires coming out however.

 

[Chryco Psycho]

The 2 smaller red wires are for the key in ign buzzer , it depends how far you want to go but you could replace the ign switch & the under dash harness , M&H is probably the best product from Year one , Evans also has the harness .
If you buy through Roseville Moparts you will get a discount .

 

[moparleo]

Safest bet is to replace the harness. If you have shorted part of it, you don't know what other problems are lurking under the tape and insulation elsewhere. Not cheap but a great investment for the future. Electrical demons are the number one problem on these older cars.

 

[72RoadRunnerGTX]

Common issue, those Molex connectors were/are underrated for the ignition switch current loads. The red 12ga wire with the tape on it (in the background of your first picture) was at that heat damaged location, is the unswitched power supply to the ign switch. Replace the connectors with a higher current rated connector, like Anderson Power poles. As mentioned, the small red wires are the igh key in switch, the smaller orange leads are the column shift indicator illumination lamp.

 

[340challconvert]

Already suggested; I would replace the harness.
Not worth putting your car at risk; many have found out the hard way with the loss of their car due to a fire.

Potential vendors;
EvansWiring.com : Product Catalog

And of course Roseville:
70 E-Body Rallye Dash Harness | Roseville Moparts

 

[70chall440]

If that is the only damage then use the Anderson connectors or get replacements and fix those areas; if there are only wiring issues then replaced the harness.

 

[ChallngeAccpted]

Ooo I like those Anderson connectors. But like I mentioned earlier, I daily drove her for months and everything worked, and i mean everything. But I am fully restoring the car now so I would like to make sure I dont start a fire lol. I am going to be performing the MAD bypass and install headlight relays very shortly here. Just messaged crackedback so I am hoping to buy his. Thank you everyone, I'd rather pay several dollars for those nice looking Andersons than $500 for a new wiring harness!!

 

[72RoadRunnerGTX]

Not a fan of the “Mad bypass” at all and the false premise that the ammeter on these cars will spontaneously combust if you don’t do the bypass. Better to address the real weakness, the charging system bulkhead connector terminals. To be clear, the charging system output circuit has nothing to do with the failure of the ignition switch Molex connections, separate issues altogether.

 

[HooToTheCore]

That 4-pin connector looks like Cruise Control. Is you car equipped with cruise control?

 

[ChallngeAccpted]

That 4-pin connector looks like Cruise Control. Is you car equipped with cruise control?

No I wish lol. But I want to know two things. 1 is what wire burned in the second picture. And 2, I I don’t understand how those two red wires from the column turn into the black and brown. The PO kept this car very original which I appreciate but he did clearly have to solder the red constant 12v wire that burned.

 

[ChallngeAccpted]

Not a fan of the “Mad bypass” at all and the false premise that the ammeter on these cars will spontaneously combust if you don’t do the bypass. Better to address the real weakness, the charging system bulkhead connector terminals. To be clear, the charging system output circuit has nothing to do with the failure of the ignition switch Molex connections, separate issues altogether.

I have just heard so many good things about the bypass. I did it on my 68 Barracuda since I upgraded to a 60 amp alternator with the appropriate sized power wire. On this car, I really only plan on putting in a simple stereo with 6x9s, MSD box, and my car has factory AC. So the bypass seems necessary to me

 

[72RoadRunnerGTX]

As I mentioned before, the cavity that overheated and separated is where the 12 ga red wire terminals was located originally, it’s been bypassed.

Unlike more modern cars, wire color coding at various legs of the same circuits can and will change on these cars. Again, the small red wires are from the key in switch, the black wire runs to the key buzzer/horn relay.

There is nothing necessary about the “Mad bypass” as it relates to the ammeter, especially without preexisting heat damage. No reason you can’t have higher than stock loads, alternator capacity and a fully functional ammeter. Wired correctly, the added loads will have nothing to do with the ammeter.
Some light reading,
BYPASS the AMMETER? (1969 A12)
The Chargeless Charger
The dreaded “ticking time bomb” factory Ammeter

 

[ChallngeAccpted]

Oh I see, it used to be one single connector. I was thinking it was two separate connections. Thank you Sir. I think I will get those Anderson connectors and fix the current harness then.

 

[Raycuda]

I did the Mad bypass and installed the headlight relays. Another benefit is that my headlights are MUCH brighter.

 

[ChallngeAccpted]

I did the Mad bypass and installed the headlight relays. Another benefit is that my headlights are MUCH brighter.

Yes those are both on my list. Currently my car is 150 miles away from me as I am in the process of moving. I am only getting to work on her once a month or so. The entire dash will be coming out shortly so I can rebuild the heater and AC boxes, replace the dash pad, and paint the dash frame. While I am in there I will look for any other potential fire hazards.

 

[moparleo]

Look, nobody wants to spend money. But choose your battles wisely.
In the grand scheme of things you will replace things during a "restoration" that aren't really "necessary". But some things are. Do your car and yourself a favor and don't cut corners on the wiring.
Plastics and insulation degrade over time and these harnesses are over 45 years old. New "quality" harnesses have no corroded connections. No hidden breaks under the tape/insulation. Modern plastic/insulation chemical formulations more resistant to degrading than old materials. Do it correctly and you will only do it one time. No second thoughts.
"The quality is remembered long after the price is forgotten." No down side to doing protective changes.
Dash fires are not myths. I have experienced 2 in my lifetime.
Some things are a cost, some are an investment....
There are guys who never had a fire, or a ticket, or an accident or ...Some are more lucky than others.

 

[moparroy]

Evans helped me out with a number of items for my Cuda harnesses I reconditioned last summer - more around the bulkhead connector - but he was very helpful.
My steering column connectors were fine knock on wood. With these old connectors problem can be as much the oxidation of crimped connections as the connector itself. Once they start they just get worse - more heat more oxidation more resistance more heat etc. I soldered all the pins I could on mine including old ones and any I replaced. I do seem to recall I had a challenge getting those round molex pins out - not sure I got to solder those - this makes me think to take another look. The only really bad connector pins I had were on the bulk head and engine alternator / ammeter charging wires. One connector had already been bypassed. FSM is pretty good at documenting the wire color changes - well in 1974 anyway - I think I did find a couple exceptions though.

 

[72RoadRunnerGTX]

I’ll take a 50-year-old original wiring harness in good rebuildable shape, that has not been exposed to excessive levels of moisture, uv light, heat, and abuse, anytime over any “quality” reproduction available today. In this case simply replacing the original ign switch Molex connection with another identical reproduction Molex connector will only lead to another failure, as they did back in the day when these cars were only a year or two old. Those terminals will not/never did handle the normal ign switch current loads.

Dash fires don’t just happen for no reason on older vehicles with a well-maintained electrical system, even with properly designed modifications. In 50+ years, I’ve never experienced a “spontaneous” electrical fire in any of the cars I’ve owned or worked on.