I bet it's the bulkhead connector

[myk]

I've got no power anywhere.  I tested the negative battery cable and that's good.  There's power to the starter relay-I'm not sure which terminals are supposed to have power but some of the terminals do so I assume that's fine.  The ammeter wires behind the dash are spliced together so I'm sure that's not the issue.  I've always had trouble with the bulkhead connectors, which usually leaves the car with NO power anywhere.  I've always brushed the contacts and tried to keep them clean; they look fine, but now I just can't get the car powered at all.  Which wires or contacts are responsible for carrying power into the car?  I lost my shop manual years ago and I'm sure it's one of the wires in the middle bulkhead connector/harness, but I don't remember which specific wires need to have a good connection to deliver power.  If I could identify which wires are responsible for carrying power would I be able to just splice a nice, fat, healthy piece of fresh wire between the two to make a good connection?  Any advice is appreciated-thanks in advance.

-Edit: I took to cleaning the terminals on the harness and bulkhead again and the car immediately had power and started.  HOWEVER-I have a wire that runs from the positive battery terminal to the starter relay (I think) and the wire got really hot.  Does that mean that the wire is bad?  That also indicates a bad connection/high resistance, right?

[Surf Charger]

Could it be possible that the fuseable link between the solenoid and the bulkhead wiring harness is bad?

[myk]

There's no fusible link between those two points.  Back in the day when I didn't work on my own cars I took it in to an electrician and they removed it, telling me that a straight wire is better...

-Anyway got it running but there has to be a better way to set this up-I still need to identify what wires are responsible for carrying power to the car, but I don't want to rely on those stupid connectors anymore...

[myaerocars]

I had an ongoing problem before like this except car would die while in motion. No power to anything.. even the dome light. 


I did find it was the bulkhead connectors.   I  removed one at a time and lightly sanded the corrosion off the tabs and them coated them with die electric grease.  I also very "slightly" tweaked the connectors with  a long nose pair of pliers to make them a little tighter.

no problems in the last 5 years since. 

Hope this helps some.

Godspeed,
JON

[68neverlate]

There are two wires in the middle connector that carry power into and out of the cab... one is red (coming from the battery via the starter relay), the other black (from the alternator).  They are the two that are visibly bigger wires... the red should be the one at the top right of the middle connector, the black is second from the left on the bottom on that connector.

Hmmm... if someone replaced the fusible link with a straight piece of wire and told you that was better, they aren't much of an electrician.          If I were you, I'd get that fusible link put back in... it's there to protect your wiring and your components!  If it blows, then there's another problem that you need to track down.  Replacing the link with straight wire is like treating the symptom, not the cause.     

Your on the mark with the hot wire... it's created from resistance which can be created by a bad connection or a run-a-way circuit (short) which causes more current to flow through the wire than it was designed for.  Once the heat starts, it creates more resistance, which in turm creates more heat, which creates more resistance... etc..  This condition is called a thermal meltdown... and it's the worst thing that can happen to your electrical system.  That's what the fusible link is there to guard against... it blows and stops the current from flowing before another more expensive part of your electrical system blows up. 

If you've had issues in the past, I'd consider bypassing the bulkhead connector altogether with those two wires....       

[myk]

Thanks guys.  Yeah I remember an electrical parts vendor that wrote articles about bypassing the ammeter, upgrading the headlights with relays and even bypassing the bulkhead wiring by joining, soldering and then shrink-wrapping the harness wires together for a bullet-proof connection but I don't remember the site.  I think bypassing the bulkhead connector is the way to go-I HATE THOSE THINGS.  Do they make repro's of those things yet?  Not that I'd buy them, but I can only imagine how hard it must be for guys trying to keep their cars original.

I had an ongoing problem before like this except car would die while in motion. No power to anything.. even the dome light. 


I did find it was the bulkhead connectjavascript:void(0);ors.   I  removed one at a time and lightly sanded the corrosion off the tabs and them coated them with die electric grease.  I also very "slightly" tweaked the connectors with  a long nose pair of pliers to make them a little tighter.

no problems in the last 5 years since. 

Hope this helps some.

Godspeed,
JON

Yeah I've had that happen to me in motion also, but not too often, thank the almighty...

[Surf Charger]

There's no fusible link between those two points.  Back in the day when I didn't work on my own cars I took it in to an electrician and they removed it, telling me that a straight wire is better...

Interesting. Mine has a fusible link between those two points. So its better without?

[A383Wing]

that fuse link is there for a reason....to stop car from burning down if something shorts out

Bryan

[myk]

Exactly.  There needs to be a fuse or fusible link there-better safer than sorry.  As I said there was a time when I couldn't tell the difference between a tit and a differential and I was at the mercy of repair shops and dealerships.  The electrician that removed the fusible link is also the same jerk that nonchalantly told me he raced a 5.0 fox body and an LT1 Camaro with my Charger and told me I had a strong car but new muscle cars are better...

[doctor4766]

Your GF has a nice set of differentials

[jlatessa]

C'mon guys, leave the crude stuff out.

The link you want about the bypass is in MAD Electrical , or something like that...do a search and good luck.

Joe

[Brass]

Here is the MAD article:

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

A couple suggestions...  Route the soldered and shrink-wrapped wire through the grommet instead of drilling through the bulkhead.  Also, rather than splicing the ammeter wires together, a better way to do that is to tighten both wires onto the same post at the back of the ammeter.  Strong connection, safe and easy. 

[myk]

A couple suggestions...  Route the soldered and shrink-wrapped wire through the grommet instead of drilling through the bulkhead.  Also, rather than splicing the ammeter wires together, a better way to do that is to tighten both wires onto the same post at the back of the ammeter.  Strong connection, safe and easy. 

Yes, thank you!  MAD electrical.  Also, thanks for the idea about routing the wires through the grommet-I don't want to drill through the firewall just yet.  Question though: I thought that any sort of current going through the ammeter was the fire hazard that everyone is so worried about?  If I just bolted the two wires together onto the same post on the ammeter wouldn't that still represent a possibility of a fire hazard?

And uh, yeah those differentials... 

[Brass]

All I can tell you is my ammeter got pretty hot when it was hooked up.  Now it seems fine.  The current isn't actually passing through the gauge itself, which I believe is the trouble-maker.  Instead, both wires are securely tightened down together with a solid connection and well away from anything else.  Hopefully someone will correct me if I'm wrong about this being reasonably safe.

[myk]

Oh no doubt it was hot.  What I understood was that the ammeter just needed to be taken out of the equation altogther.  But, I DO like the idea of those wires being bolted onto something, rather than just floating around in that spaghetti dish of wires...

[doctor4766]

Great idea from Brass there.
As long as they're only connected to one side there won't be any issues as the current will not pass through the ammeter.

[myk]

Riiiiight.  The ideas is ON the ammeter, not THROUGH it.  Unless anyone has any objections...

[doctor4766]

Yeah it's basically a secure hold down point.

[Bob T]

Myk, I've just been through the wiring replacement/make safe gig as well. The original problem was the red and black wires routed to and from the ammeter via the bulkhead connections, these are ( in my humble view ) only rated for 10-15 amp max and yet the whole system of maybe 25A was routed though it and more if it was an a/c car. The usual result was burnt out loom and worse, both my Chargers have had the same thing but this one was worse
Yes, a good fix is bolting both on one post, I rewired mine and bypassed/reconfigured this section and left the ammeter out, have a look on the wiring threads for some good tips from Nacho and others 

[myk]

That's a great idea.  I also went ahead and picked up the shop manual on CD; I don't know if you guys approve of that stuff or not, but it beats lugging around that dictionary sized shop manual like I used to back in the day.  My main concern now is to find and splice together those two wires that are probably causing all the ruckus in my bulkhead connectors.

So for clarity's sake, it's the RED wire coming from the starter relay and the BLACK wire coming from the alternator (according to the shop manual it's marked "P" and "J"), that I have to eliminate the weak connectors and splice together with the matching terminals from the bulkhead connectors?  Ugh.  I guess this means I have to take my dash off again...

Or...do I just pull the wires out of the bulkhead connector?  And one more question: are these the two wires that are responsible for carrying power throughout the car and therefore causing these power outages, or are there other wires/circuits that can cause these outages as well?  Again, thank you all for your input...

[Paul G]

This is what I did and would highly recommend we all do. Get rid of the old wire from the starter relay and from the alternator all together. It has served it's useful life and is time to be put to rest. And by all means, replace that fusible link. If you are serious about an original look, replace the harness with new. But you are limited to never adding accessories like an amp, CD player or anything electric and expect it to work properly. 

Go to Ace Hardware and get some 10 gauge wire, 15' should be enough. Since you already bypassed the amp gauge you are good to go there. Cut open the tape on the old wire loom, remove the wire from the alternator all the way through the bulk head connector. Run a new 10Gauge in it's place. Connect it with a new crimp lug on the alternator, use a crimp type but connector, or solder it back in to the circuit behind the dash. Do the same thing with the wire going to the start relay. You can drill through the bulk head connector, or go through a grommet. Drilling through the BHC will give it a more factory correct look if that matters to you. Get some cheap black electrical tape and tape the loom back up. If you want to dress up the wiring while you have it apart, you can clean up the wire that is exposed with some simple green cleaner.  Makes it pop at car shows.

I put an auxiliary fuse block under the dash while I was doing it. Ran the alt wire and the bat wire to the screw terminal on the new fuse block, along with a heavy new wire to feed the original fuse block. This bypassed everything going up to the amp gauge and fed good power to the original fuse block. I run an auxiliary electric radiator fan, a CD stereo, electric exhaust cutouts, idle solenoid for A/C, all fused from the new fuse block now and still maintain 12 to 13 volts to it all. Good clean safe power inside the car.

[ugly2u]

Highjack!
Thank you Myk and DC.com for the great info!

I just installed a new M&H harness, and nothing, would not start! No electricity to the key switch. I read a few articles, and BAM! there is the info I needed from Myk. Bypass the ammeter and wire the black and red together. Starts now....

thanks

[nvrbdn]

just markin to keep for reading

[myk]

I just wanted to make sure I understand the layout/routing on this series of wires that is the problem we've been talking about: alternator output to bulkhead connector, bulkhead connector to ammeter, ammeter to dash wiring, dash wiring to bulkhead connector, bulkhead connector to starter relay?  Someone correct me if I'm wrong.  Now I'm shipping my car off next week to get rewired but I'm going to put in some new wire to hold me over until I get there; can't imagine anything worse than losing power in the middle of a cruise/car show....  

Edit: I want to install a newer, blade fuse type of wiring system, so should I insist on a Painless, Ron Francis, EZ wiring or what?  Another thing: if I install an aftermarket wiring kit I can say goodbye to my factory diagrams, right?  Also, are any of you running an electric fuel pump?  The shop mentioned I might want to look into that since the car will be there, but personally I HATE electric fuel pumps and don't see any sort of mechanical gain by going electric.  Finally, what about externally or internally regulated 'alts?  Right now I have a 90 amp (I think) 'alt that's externally regulated but it's been suggested I think about going single wire.  I can see the advantage of the single wire because of not having to worry about the external regulator, but are there any other compelling reasons to switch to an internally regulated, single wire 'alt?  Thanks again, guys...

[Nacho-RT74]

NO NEED TO BYPASS THE AMMETER IF YOU HAVE ENOUGH ALT POWER TO FEED THE CAR, but allways recomemnded bypass or double the wire between alt and amm. In some cases, isn't even necesary the double wire to batt/starter relay.

if you need the MADelectrical mod, is because you never got enough alt and all power coming from batt was running to feed the main splice located between amm and alt, through the ammeter. PLUS the spikes of power coming from alt to rescharge the batt, when reving up

[myk]

Ok, the car's getting completely rewired however the shop and everyone else in San Diego that knows the car is BUGGING me to go from an externally regulated 'alt to an internally regulated one.  I just installed my 90 amp externally regulated 'amp less than 1000 miles ago and have no issues with it, so personally I see no need to switch to the internally regulated one.  Opinions, guys? 

[Paul G]

There is nothing wrong with your externally regulated alt. It just requires wiring between the alt and the regulator on the fire wall. No real reason to spend more $$ on a new alt. Unless you want to switch it out anyway and give the 90 amp unit to one of us. 

[myk]

Would any of you want it?  I don't see why there're so many people hot and heavy for internally regulated 'alts...

[Nacho-RT74]

To me, is wonderfull when reg fails no need to remove alt and open it .

However I haven't needed to change the reg in maybe... lets say NEVER since I rewired my car. Only has changed it to the Mopar replacement part to make an older school look, instead replacement chromed unit, with penstastar piece on engine bay

[A383Wing]

if it ain't broke...don't touch it (referring to alternator choice)

Bryan

[myk]

To me, is wonderfull when reg fails no need to remove alt and open it .

However I haven't needed to change the reg in maybe... lets say NEVER since I rewired my car. Only has changed it to the Mopar replacement part to make an older school look, instead replacement chromed unit, with penstastar piece on engine bay

Well that's my argument against the internally regulated 'alts: if the regulator goes out chances are you're going to have to replace the whole damn thing, whereas replacing an external regulator isn't so involved.  Well, at least there'll be less wires running around in my engine bay...

[thrillbilly]

I did the MAD electric fix to bypass the bulkhead connection.  Mine was melted and I was getting electric "spikes", all my gauges would peg themselves and come back to normal.  I completely bypassed the ammeter, the wires were getting melted going into that also.  I would NOT use a crimp only butt connector on any high voltage wire, it needs to be crimped with a non-insulated connector, then soldered and insulated.  I never wanted to solder anything until I bought the solder gun, it is super easy and a way better connection.  I added several relays for my a/c blower and all my headlights, huge difference.

[myk]

I did the MAD electric fix to bypass the bulkhead connection.  Mine was melted and I was getting electric "spikes", all my gauges would peg themselves and come back to normal.  I completely bypassed the ammeter, the wires were getting melted going into that also.  I would NOT use a crimp only butt connector on any high voltage wire, it needs to be crimped with a non-insulated connector, then soldered and insulated.  I never wanted to solder anything until I bought the solder gun, it is super easy and a way better connection.  I added several relays for my a/c blower and all my headlights, huge difference.

Wow good job-your car sounds solid, electrically.  Meanwhile, my new EZ wiring harness has literally "turned the lights on" in my car.  Anything eletrical is rock solid/stable and it runs that much better.  Sure, I had a 90 amp 'alt to help out before, but with the new 130 amp 'alt, fresh wiring and lotsa new sockets, switches and whatnot it's in the best shape of its life, electrically.  I must say that the super-loud electric fuel pump is super annoying, though...

Edit:  Wow!  I didn't know we had a map light!