No headlights

[70furyiii]

Yes all of that looks correct and yes the amp gauge is the battery gauge. If you do not have power at the red wire on the amp gauge go under hood and find the big red wire coming out of the bulk head connector. Up on the fender well you should find a connector and a fusible link. Check for power here and inspect the fusible link if it looks burnt it needs to be replaced. Make sure you wrap some tape around those exposed wires under the dash before replacing the fusible link because it that splice touches ground it will blow the fusible link again.

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Ok, I am making progress I think! I have traced all the wires that should have power to the black wiring going out to the engine bay. There is no power coming from the wire, which powers everything that is not working. That wire runs directly to the alternator. Does that sound right? Can I swap that wire out and run it to the battery with an in line fuse? Yes the wiring is a mess...I had to cut all the tape off to trace wires and I absolutely plan on re insulating the wires and the connectors. I can't thank everyone enough for their help on this!!

 

[1970FuryConv]

Ok, I am making progress I think! I have traced all the wires that should have power to the black wiring going out to the engine bay. There is no power coming from the wire, which powers everything that is not working. That wire runs directly to the alternator. Does that sound right? Can I swap that wire out and run it to the battery with an in line fuse? Yes the wiring is a mess...I had to cut all the tape off to trace wires and I absolutely plan on re insulating the wires and the connectors. I can't thank everyone enough for their help on this!!

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The wire you are talking about is R6A-10BK at the ammeter, upper left in the diagram below. It runs through the bulkhead connector #16 and directly to alternator output. Look 4 posts down to #26 and another member has provided a diagram of the bulkhead connector.
Sounds like a problem with corrosion at the firewall bulkhead connector behind the fusebox.
If you have power on the engine side of the firewall at that wire, but not on the passenger side, you have found the problem.
You can try removing the connector and cleaning both sides of the connector.
2nd option: You can cut both sides of the wire, bypass the firewall bulkhead connector and run the wire through a grommet in the firewall.
3rd option: run a 2nd wire from the alternator output to the starter relay post that recharges the battery.

 

[3175375]

B

Sounds like a problem with corrosion at the firewall bulkhead connector behind the fusebox.
If you have power on the engine side of the firewall at that wire, but not on the passenger side, you have found the problem.
You can cut both sides of the wire, bypass the firewall bulkhead connector and run the wire through a grommet in the firewall.
Another option is to run a 2nd wire from the alternator output to the starter relay post that recharges the battery.

e careful. You don’t know what other ‘customizations’ exist. Take it slow.

 

[MONC440]

Ok, I am making progress I think! I have traced all the wires that should have power to the black wiring going out to the engine bay. There is no power coming from the wire, which powers everything that is not working. That wire runs directly to the alternator. Does that sound right? Can I swap that wire out and run it to the battery with an in line fuse? Yes the wiring is a mess...I had to cut all the tape off to trace wires and I absolutely plan on re insulating the wires and the connectors. I can't thank everyone enough for their help on this!!

View attachment 727063

View attachment 727064

The red wire is the supply wire from the battery to the amp gauge. The black wire is not the supply wire. The way it works is red wire from the battery, then fusible link, then bulk head connector, then amp meter, then a black wire out of the amp gauge to the splice that supplies the headlights, alternator, and other things. You need to get power to the red wire at the amp gauge first!

 

[MONC440]

Sounds like a problem with corrosion at the firewall bulkhead connector behind the fusebox.
If you have power on the engine side of the firewall at that wire, but not on the passenger side, you have found the problem.
You can cut both sides of the wire, bypass the firewall bulkhead connector and run the wire through a grommet in the firewall.
Another option is to run a 2nd wire from the alternator output to the starter relay post that recharges the battery.

I think we are going to confuse the OP. The black wire to the alternator comes from the amp gauge not to the amp gauge.

Check the red wire from the battery and fusible link FIRST!

 

[MONC440]

Basic electrical trouble shooting is starting at the power source, in this case the 12 volt battery, and travel to the component, in this case the amp gauge, and check every connector along the way. When you find where you have no power you found the issue. Or you can start at the component and work tward the power source but if you have a splice you need to know what path to follow by knowing how to read a wiring diagram.

I have written many diagnostic trouble shooting charts for everything from automotive to marine refrigerators and the basic principle is the same.

You could very well have a bunch of corrosion at the bulk head connector, very common on our Furys, but do this first.

1. Start at the battery and check the red wire with the fusible link, check at the connector before the fusible link in the picture I provided. If power go to step 2, in no power repair wire.

2. Check the fusible link for obvious signs of damage, and probe wire after the fusible link. If power go to step 3. If damaged or no power after the fusible link replace the fusible link.
3. Disconnect the connector at the bulk head, inspect the connection for damage or corrosion and check for power at the red wire. If clean and have power at the red wire go to step 4. If corroded and no power clean the connection and retest for power, if still no power repair red wire from fusible link.
4. Reconnect bulk head connector. Move to under dash and check for power at the red wire (pin 28 see image below) coming out of the bulk head connector going to the amp gauge. If no power the problem is in the bulk head, repair as needed. If you have power at pin 28 go to step 5.
5. Check for power at the red wire on the amp meter. If not power repair red wire form bulk head to amp gauge.

 

[70furyiii]

Basic electrical trouble shooting is starting at the power source, in this case the 12 volt battery, and travel to the component, in this case the amp gauge, and check every connector along the way. When you find where you have no power you found the issue. Or you can start at the component and work tward the power source but if you have a splice you need to know what path to follow by knowing how to read a wiring diagram.

I have written many diagnostic trouble shooting charts for everything from automotive to marine refrigerators and the basic principle is the same.

You could very well have a bunch of corrosion at the bulk head connector, very common on our Furys, but do this first.

1. Start at the battery and check the red wire with the fusible link, check at the connector before the fusible link in the picture I provided. If power go to step 2, in no power repair wire.
View attachment 727069
2. Check the fusible link for obvious signs of damage, and probe wire after the fusible link. If power go to step 3. If damaged or no power after the fusible link replace the fusible link.
3. Disconnect the connector at the bulk head, inspect the connection for damage or corrosion and check for power at the red wire. If clean and have power at the red wire go to step 4. If corroded and no power clean the connection and retest for power, if still no power repair red wire from fusible link.
4. Reconnect bulk head connector. Move to under dash and check for power at the red wire (pin 28 see image below) coming out of the bulk head connector going to the amp gauge. If no power the problem is in the bulk head, repair as needed. If you have power at pin 28 go to step 5.
5. Check for power at the red wire on the amp meter. If not power repair red wire form bulk head to amp gauge.

View attachment 727068

 

[70furyiii]

So here is what I have come up with: When I bought the car, the owner said the headlights and tail lights stopped working after he had someone put a new ignition switch in. Apparently the installer just ran a single hot wire from the battery to power the ignition switch. The red wire that should be in the 28 spot on the diagram was burnt up completely and not connected to anything...It was cut under the dash. The entire connection that I took a picture of (the one that is bare with multiple wires fused together) doesn't have power at all.

I ran a hot wire from the battery to where the red wire should be going to on the amp gauge....the wire burnt up instantly. That is where my issue is now. The black wire coming out of the amp gauge is going to the alternator so I wasn't sure if i put too much power in resulting in the wire melting. Should i just run the new power wire from the battery to that connection under the dash that was originally powered by the wire coming out of the bulkhead?

 

[HWYCRZR]

Actually the alternator is feeding voltage through the black wire to the ammeter and the ammeter is supposed to tell you the difference between charging power (black wire) and battery power (red wire. Basically if your battery voltage is lower than your alternator output, the power differential flows through the ammeter showing charging until your battery voltage equals alternator output. If your ammeter is defective or shorted to ground you will have heat which burns up wires. This is why the fusable link (on red wire circuit) and voltage regulator (limiting voltage on black wire) is important.

Sometimes defective circuits and connections are why some people do an ammeter bypass. However a proper working ammeter and clean terminals is the best solution in my opinion. I would have to go through the service manual to check how to test the ammeter. Sometimes you can do a quick bypass of the ammeter by connecting the red and black wires on the back of the ammeter to the same terminal this takes the ammeter out of the equation.

But if you are getting a hot melted wire you have a short to ground somewhere. It could be the ammeter or somewhere else.

 

[MONC440]

So here is what I have come up with: When I bought the car, the owner said the headlights and tail lights stopped working after he had someone put a new ignition switch in. Apparently the installer just ran a single hot wire from the battery to power the ignition switch. The red wire that should be in the 28 spot on the diagram was burnt up completely and not connected to anything...It was cut under the dash. The entire connection that I took a picture of (the one that is bare with multiple wires fused together) doesn't have power at all.

I ran a hot wire from the battery to where the red wire should be going to on the amp gauge....the wire burnt up instantly. That is where my issue is now. The black wire coming out of the amp gauge is going to the alternator so I wasn't sure if i put too much power in resulting in the wire melting. Should i just run the new power wire from the battery to that connection under the dash that was originally powered by the wire coming out of the bulkhead?

Yes if you ran a new wire from the battery to the red side of the amp gauge and it melted immediately then you have a dead short to ground someplace. Let me dig through the wiring diagram later tonight and I will see if I can steer you in the right direction.

 

[Big_John]

I ran a hot wire from the battery to where the red wire should be going to on the amp gauge....the wire burnt up instantly. That is where my issue is now. The black wire coming out of the amp gauge is going to the alternator so I wasn't sure if i put too much power in resulting in the wire melting.

You have a short to ground somewhere.

Should i just run the new power wire from the battery to that connection under the dash that was originally powered by the wire coming out of the bulkhead?

No. Chances are that short to ground is still going to bite you, possibly worse.

Do you have the Factory Service Manual for this car? Service Manuals – MyMopar will have a nice digital version. What I suggest is you download it and print out the wiring diagrams for the dash and under the hood. Then use a highlighter on the wiring runs to figure out where you are.

I think that somewhere there's a short in one of the wires that are spliced into the black wire coming from the ammeter. You'll have to chase those wiring runs and figure out what's at the end.

 

[70furyiii]

Yes if you ran a new wire from the battery to the red side of the amp gauge and it melted immediately then you have a dead short to ground someplace. Let me dig through the wiring diagram later tonight and I will see if I can steer you in the right direction.

Thank you so much!!

 

[70furyiii]

You have a short to ground somewhere.

No. Chances are that short to ground is still going to bite you, possibly worse.

Do you have the Factory Service Manual for this car? Service Manuals – MyMopar will have a nice digital version. What I suggest is you download it and print out the wiring diagrams for the dash and under the hood. Then use a highlighter on the wiring runs to figure out where you are.

I think that somewhere there's a short in one of the wires that are spliced into the black wire coming from the ammeter. You'll have to chase those wiring runs and figure out what's at the end.

Thank you, I will trace that black wire tomorrow and see what i come up with. This has been quite the learning experience thats for sure, but I do enjoy it!

 

[MONC440]

Thank you, I will trace that black wire tomorrow and see what i come up with. This has been quite the learning experience thats for sure, but I do enjoy it!

Always is!

So we know battery power comes in at the red wire to the amp gauge. When you replace this wire you need a heavy wire I think the factory wire is 10 gauge. So now lets look at the black wire from the amp gauge, it goes to a splice. The black wire with white tracer goes to the headlight switch, the Vitol wire goes to the horn relay in the fuse panel, the red wire also goes to the fuse panel, the black wire goes to the alternator thru the bulk head connector, another red wire going to the steering column. You said the red wire going to the ignition was bypassed because it was burnt. I would start by checking that wire is not touching a ground some place. If that looks ok, start tracing each wire leaving that main splice, one of them is grounding out. Let us know what you find.

 

[Gerald Morris]

I suspect

A lot of other things will also be dead. What works (radio etc.) and what doesn't?

Yes, although that should be insolated.

This picture bothers me a bit. Evidence of poor wiring in the twist and butt connector. You may have to pull that all out.

View attachment 727052

That butt splice connector is 1.) under sized! 2.) shows conductor to the air on both ends, either of which can short in contact with any grounded metal surface around it. 3.) shows a white #12 going in, and a red #10 going out.

You need to find WHERE that damned WHITE wire is connected on the other end. I suspect the red, going into that cable cluster leads to your ignition switch, right?

Depending on WTF the white wire comes from, you should eliminate it AND the butt splice connector. IFF you MUST use a TEMPORARY SPLICE THERE OF ANY SORT, use a 3M Scotchlok twist on connector, a RED one, until you ascertain for SURE what is supposed to feed that RED wire, which, if it's to your ignition switch, probably comes from that unholy clusterfucked series circuit off the ammeter. on the BATTERY side. Now, I don't own a 1970, but Ma Par had been in the habit of running the battery lead in RED odd that Oh So Wonderful ammeter. I rejoice that by 1970 it APPEARS they ran that in #10 AWG anyway. You NEED the Field Service Manual for your machine B'rer NewB! Get it here: https://www.mymopar.com/downloads/servicemanuals/1970_Plymouth_Service_Manual.zip Now, for the sake of sparing my /home/dir storing another fat PDF, I'll just pop open the Chrysler FSM from the same year, and we'll look at a pertinent wiring cartoon there:

Attend to that A1 wire. First, it's a 10 gauge, in RED. This comes in from the bulkhead connector, where you have a toasted #14 AWG fusible link feeding through on the engine side from the starter relay, near your battery. I saw NO WHITE LISTED ANYWHERE IN THIS DIAGRAM, but, in the interest of pure Objectivity and scientific accuracy, I admit this isn't the Plymouth manual for 1970. I admit I don't expect any big white wires showing up there either, but there's a chance I'm wrong.

The big BLUE cheap wirenut needs to go also. Again, if you MUST make a TEMPORARY WIRE JOINT, use 3M Scotchloks, and nothing else. They're among the VERY SHORT LIST of automotive rated wirenuts. Once you KNOW what each of those wires is for, either splice them together, then solder them, with good shrink wrap over the splice after, OR, BETTER YET, if possible, REPLACE them with ONE, INTACT WIRE. This likely won't do for the white-to-red connection, but at least you SHOULD ditch that white for a red of the same size, likely a #12. Make SURE.

Regarding fusible links: If you plan to just restore the car as it was constructed, you should use a #14 AWG link. You can search for, then pay an obscene price for, an NOS one, from the period, which will plug right in, OR, you can MAKE ONE, from #14 AWG fusible link wire, using a 1/4" slide connector, probably male on the link to female on the battery feed, and stuck into the bulkhead connector on the other end. That too is a 1/4" male, but you will definitely want one meant for Mopar, like this:

You can find plenty of these on eBay. Get some for the little wire, and some for the larger sort too. You'll be glad you did when you need to replace something. There are plastic hoods to slide over the terminals, just like what Mopar used, but with a little care, you can recycle the old ones, if you like. I don't like the idea of paying $10 for a single bit of nylon to cover my terminations, so I recycle. The price is somewhat justified by the fact that it takes money to tool up and run a batch of these old restoration terminal condoms off.

I actually run my fusible links at my battery, protecting my 3 main current carrying conductors from that point. It doesn't matter where, so long as it works when needed. I still have the old 16 AWG link on my bulkhead connector, but I very sensibly have disconnected all that old, under sized ****, and ran nice large conductors appropriate to my current source and loads. Consequently, I have very good voltage throughout my system. You certainly need to know what you're doing before upgrading or re-routing main current sources, but I actually do. Check the size of your charging conductor off your alternator sometime, and make sure it's proper for the ampacity of that alternator.