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1971 Roadrunner electrical issues

S

SirSharker

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So, I picked up a pretty 71 roadrunner as a fun car. A few minor issues as expected but now I have a major electrical issue. Battery drains while at rest, wiring has been messed with over the years and is a bit of a mess. When I jumped the car the other day I noted the red wire coming to the firewall started to smoke. I pulled the cables and disconnected the bat.. Am I running a fire issue or just too much juice from the jumper cables?
 
A few photos. I think I need to wire past the dash gauge, thoughts?

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You have 3 harnesses under the hood. Wiper harness, Engine and front end lighting. The rear lighting passes through the lower left kick panel and runs under the wire shield just under the sil plate all the way to the back.

You should download the shop manual for the car and chase down the demons.. I love rewiring cars.. Its fun to me. Here is a link to the shop manuals.

http://www.mymopar.com/index.php?pid=109
 
well, it seems you got a short somewhere. and it got some previouslly to because that red melted wire should be blue being a fuse link... replaced maybe with a regular wire instead a fuse link ? wrong!

to get that wire melted like that is a bad signal... could be ammeter isolators meled and shorted to cluster housing ? practically 90% of the car is fuse protected but the charging system, ignition system and headlights... those are protected by the fuse link
 
BeepBeepRR said:
I love rewiring cars.. Its fun to me.
Click to expand...
+1
I could live from that if living in USA I guess, with all the tools and materials handy!

on a side note, If is what I told ( ammeter isolation fail ) is just about replace isolations and the propped mantenience to the gauge. The gauge itself is hard to beat, but related stuff about the poorly charging system balance from factory causes damages all around, like bulkhead ( as you can notice ), and ammeter studs and terminals. Read this and understand how it works and what an amm reading means:

http://www.dodgecharger.com/forum/index.php/topic,33574.0/all.html

with a better alt and good paths you won't have to worry about that anymore, but after 50 years with abuses and based on the wrong alt selection output from factory is normal you can get those fails at this moment. When an engine begings to smoke, you rebuild it... well same to the wiring!
 
What Nacho said, there must be a short somewhere. I had almost the exact same issues on my 73, and it was because someone had added aftermarket stereo equipment and overloaded the system and fried everything, the exact same wires you show. This forced me to install all new wire harnesses when I did my restoration, and I also installed the proper amp alternator, as a stock setup car, it doesn't need more than 60amps. If you want to do more than I would look at amp gauge bypass and other upgrades that can be done. If stock, spend the money and get new M&H harnesses, that eliminates a lot of guess work, and gets rid of all the crusty hardened and corroded 47 year old wires and bulk head connections.
 
From the looks of your wiring I wouldn't leave the battery hooked up or run it until you fix what you have or get another harness. I suggest keeping a fire extinguisher handy,just in case
 
no need to bypass ammeter and as I explained on my DC.com thread, is just about the correct load balance from the sources and get better the paths including ammeter mantenience. Get an alt able to feed at iddle the more accesories as posible will be the main success on this. An stock 60 amps will provide 30-35 alts iddling. The more the best, opposite what most of ppl thinks. My advice is get an alt ABLE ( which doesn't mean will be steady there, amperes are requested by the devices, not pushed in by the alt ) to give 45 to 55 amps depending if AC or not as minimun
 
Thank you all for your reply. An Nacho, thank you for the link to the other write ups. The parallel wiring is what I was thinking I had to do, with the bad and old wires it seems like a good idea to get a new harness ordered as well, Thoughts?

Also have a question on the starter relay. There are two posts on the bottom, neither were connected when I got the car. What are they for?
 
They are the relay’s primary terminals, one connects to the neutral safety switch (or clutch pedal switch for 4-speeds), the other is the yellow lead (starter) from the ignition switch.
 
SirSharker said:
Thank you all for your reply. An Nacho, thank you for the link to the other write ups. The parallel wiring is what I was thinking I had to do, with the bad and old wires it seems like a good idea to get a new harness ordered as well, Thoughts?
Click to expand...

Could or could not. Diagnosis first. Wiring is easy to do really, just need patiente. You can fix a harness with just $10-15 instead replace a full harness on $150-200


SirSharker said:
Also have a question on the starter relay. There are two posts on the bottom, neither were connected when I got the car. What are they for?
Click to expand...



cableado de arranque.jpg
 
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Ahhh.. so this is why I could start my car while in drive. Scared the crap out of me when I did it on accident.. I will fix that connection too.
 
One of your above pictures appears to show the yellow lead connected to the solenoid terminal, not only will it crank no matter what gear, all solenoid current would be routed through the bulkhead connectors, dash wiring, and ignition switch. The primary purpose of the starter relay is to not have this current draw on those wires. Be sure the check the ignition switch Molex connectors at the bottom of the steering column for heat damage/high resistance.
 
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about the burn spots... if damages are just on terminals and rest of wire are still good you can replace bulkhead itself allong with terminals ( male and female ) allong with isolators to make a full system refreshment instead get a full harness setup. Depending on your skills to make that

https://www.ebay.com/itm/Bulkhead-C...h=item287130a693:g:yscAAOSw4GVYIj0R:rk:2:pf:0

https://www.ebay.com/itm/Mopar-Engi...h=item3625bbf206:g:IPEAAOSwwbdWKCr9:rk:4:pf:0

https://www.ebay.com/itm/1969-70-71...=item20dd16d926:g:IaAAAMXQMXRQ42Wv:rk:34:pf:0

even the gaskets

https://www.ebay.com/itm/DMT-Mopar-...=item43a463abc1:g:CQcAAMXQjWtRQR7K:rk:20:pf:0

these links are just to show they are available, but some stuff can be found cheaper ( terminals at some local electrical shop for example ) and get just one supplier for all the plastic parts

https://www.megapartsusa.com/products.asp?cat=749

https://www.megapartsusa.com/products.asp?cat=439

https://www.repairconnector.com/packard-56-terminals-and-housings/

http://www.texasindustrialelectric.com/_packard_terminals.asp
 
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