I thought, I'll just clean a bit my Challengers dashboard wire harness...

And I learned, that one simply HAS problems with the bulkhead wire connector. It has not a really reliable design.

Not only its dirty like hell - after cleaning I found pin 18 (coming from alternator) has melted away its housing.

Since I find 450+ $ a lot for an entire new harness, I'll take the challenge (well, it's the cars name, is it?) to repair that.

Cut away all the burnt plastic and clean it. Than I tried with an epoxy - mastic. Filled the entire hole and then used a screwdriver to form the duct from inside just roughly.

Then after 4 hours hardening it was time (once more) for the dremel. I just took a drill and worked carefully to model about a duct for the new plug.

It worked! Kept the duct tight that the plug seats fix. Formed a little step for the plugs barb to engage.

Not to bad, is it?

Have to admit, does look good

I've got the impression that it is hard to get only the bulkhead connector as a replacment part.

Another way would've been to move that pin to a free slot - but that's ugly since it would be in another plug on the male side. So again it was worth a try to repair something.

I used this epoxy mastic the first time. It has the advantage that one can form anything just with the fingers and any tool - it's not liquid and it's not too sticky so it keeps easy the form you give it. And it will stay hard up to 250 deg. F. But it's not that hard like polyester/fibreglass.

you might want to do the ampmeter bypass and run the wires straight thru the bulkhead without using the pin conector, I asume that burnt hole is from the 8 gauge alt wire, mine was burnt also. heres a link check it out http://www.madelectrical.com/electricaltech/amp-gauges.shtml

you mean INSIDE the cab ? on underdash harness ?

this brake lamp gets power from ign switch blue wire, being powered in RUN ( also in start being feededback from ballast resistor, but thats another deal ). This blue wire is joined with engine harness blue wire too.

Inside the cab, depending of the year, you can find another devices being feeded from this line, like buzzers, relays etc... stuff like seatbelts, low fuel ligh, some special accesories. It has its own fuse on top. If you check on back of fuse box, you'll find a fuse holder NOT ATTACHED TO ANY BUSS BAR, what gets blue wires. Cluster brake light is attached on this "fused" line too

the other fuse holder not attached to any buss bar is the cluster/dimmer lights

on standart clusters with idiot lights ( oil light ) this light is feeded from this wire too

would need to be checked and analized where exactly was and what could it be the reason, from the distance, is hard to tell.

Once I got a melt on the blue wire line ( from alt to ign key ) due a short on alternator field ( isolator got broken )

you want another good reading
http://www.dodgecharger.com/forum/index.php/topic,62772.0.html

one of the links posted there is the one you found

the other ones are some nice discussions we got here, and one is nice future uograde I have in mind for shunt setup upgrade

Thanks - I did replace the burnt wires and will just see (and do some measuring) what happens.

But back for a second to the "Parallel Wire Universum":

I understand that there are different opinions (beside many that simply cannot read a wiring diagram). My opinion is that one can keep it as simple as you mentioned: Strong enough alternator and parallel wires to the ammeter. And additionaly move all the relay stuff to the alternator side of the ammeter.

Since my car has no AC and not even a working radio (YET), I think I'll go for the 80Amp upgrade kit (together with new bearings) for the alternator.

And get some really FAT wires

I know you said this already - but won't 10 gauge wires be enough for the parallel wires??? Does it really take 8 gauge???

Can one build a fusible link himself by just inserting a short piece of thinner wire into the fat one, like 4" of 14 gauge into a 10 gauge wire?? Will that blow out in case?

honestlky if you keep the stock 12 gauge one on the original harness, 10 will be enough for the parallel, since the BIGGER PROBLEM IS REALLY at conectors at bulkhead, not just the wire itself. The thicker wire is just for headroom.

I took 8 gauge on the black side just because I had it handly from a Coronet 75/76 donor

even less necesary on cars without AC.

If you want 8 gauge, go for it. won't hurt. The problem is try to find a nice terminal for it if you want to be able to unplug the wire just right before the dash line ( grommet ) maybe for some mantenience or repair. I haven't been able to find it! so run directly through firewall without somekind terminal before. Original Mopar diagrasm with parallel wires shows a terminal there using a 8 gauge wire

Yes, Mopar diagrams... this solution wasn't made BY ME, I'm just refreshing this was an option for bigger alt car even before of the shunt kind setups... Police, cabs, Tow equipped... mostly with leece neville alts ( up to 100 amps )

On red side, 10 or 12 is also enough. No need for 8 gauge there. Remember the deal here is first feed the main splice thats why Bclack side is thicker.

fuse link... I would get a FUSE LINK, not a thicker wire. 14 or 16 gauge. A thinner wire will burn the cover and allmost never will blow, and if does, will be too late to save the short area.

Indeed, regular terminals are available for up to 10 gauge wires. I always solder them in case of expected higher current flow.

Finally one has also to keep in mind that the fat black wire will got to the ammeter - and then the old, single 12 gauge wire goes to the splice... seen it that way a second/parallel 12 gauge wire that goes directly through the firewall would also do a good job. But 10 gauge is okay, it's flexible and "handable" enough - and good available.

I will run another, third (probably 12 gauge) wire from the alt to my existing relays that feed headlight. They are already in the engine compartment and I don't bother because of that - they look cool somehow (matter of taste ). The one and only shop that I allow sometimes to work on my cars has installed them and - of course - connected to the batt junction block.

I found summit racing to be a source where I can get the stuff I need (together with a new 100 amp alternator that I decided to get after disassembling the old one yesterday ). They also sell fusible links with 14 or 16 gauge - cheap parts. Still I just wonder if fusible links are different from just being a thinner wire inserted in a fatter one and surrounded by plastic??? Are they made from different metal???

I used 8 gauge wire because beside is the one I had handly, I fit all my relays INSIDE the cab, and use the ammeter stud to splice the power for them.

If you will splice the power for relays on a third wire from alt stud keeping relays on engine bay, then you have more reasons to not need an 8 gauge wire on the parallel black. 10 will be more than enough keeping the stock 12 on harness and using the third wire to feed relays.

the stock wire is 12, gets the splice inside the cab and goes on to ammeter too... both blacks, the stock and the parallel must be still attached together at ammeter!

yes, fuse link are a ver diff metal. Something similar to the bulb filaments, but of course, lot stronger.

Note: if you can use BULLET kind terminals for the parallel wires, even better. They have by default more surface making contact between male and female, so less resistance to high loads.

I normally use those commercial color covered terminals, but after attach them, use black shrynking tube to cover them up to the wire cover. That will isolate more against enviroments elements and will cover those bright colors LOL... I hate those colors around what makes them look out of stock.

And of course, solding is allways a good idea specially if you dont have the right crimping tool for each terminal. Myself I allways sold them