I don't know who matt is. And if anybody read what I wrote I said
First I said "you have a lot of great answers here" and who is Matt?
After a fire.....
- Thread starter 64longroof
- Start date
-
ps I doubt it's mr 383S
- Joined
- Jan 8, 2012
- Messages
- 7,098
- Reaction score
- 4,247
Mr 1969383S says.
I am not Not trying to add insult to injury to the OP.
Have been running Mopar since 1980. Obviously do not have all the answers. To disagree with anyone sometimes makes you bad! I have been preaching about the 50 year old car wiring since joining this site in 2012 from looking and understanding just how bad it was on mine, and very few listen and take action. I lost one that way and it was not caused by Bulkhead overload.
If you ask to much of it, then you may find yourself in the need to re-engineer with such mods and I fully understand why this may be needed.
That being said, Having “New” good harnesses and such will keep this from happening and is very smart! Just stop for minute and Look at what you may have already spent to get there!
Like said over and over again, JMO!
I am not Not trying to add insult to injury to the OP.
Have been running Mopar since 1980. Obviously do not have all the answers. To disagree with anyone sometimes makes you bad! I have been preaching about the 50 year old car wiring since joining this site in 2012 from looking and understanding just how bad it was on mine, and very few listen and take action. I lost one that way and it was not caused by Bulkhead overload.
If you ask to much of it, then you may find yourself in the need to re-engineer with such mods and I fully understand why this may be needed.
That being said, Having “New” good harnesses and such will keep this from happening and is very smart! Just stop for minute and Look at what you may have already spent to get there!
Like said over and over again, JMO!
I'm sorry I got upset. I really am. I just try to help others. First let me say I don't know it all as I still learn something new every day. I just try to make it error proof for people so they don't have issues down the road and make it safer for everyone. There aren't many old cars that are 100% stock. What I mean by this is there isn't many old cars that haven't changed a alternator, starter, battery, a wire, light bulbs etc. So lets use his car as an example. Orignally it had about a 35 amp alternator. So the amp gauge rating say is 30-40 amps and scale would be the same. So we all know (or maybe not) about the bulkhead connectors. So lets assume (I know) at some point in 55 years the alternator was changed once or twice so now what amp alt. do we have? So as our old cars sit for a while the battery loses some or all of it charge, so it gets jump started or put on the charger for 10-30 minutes or so to get it fired up and what if the battery is no longer up to snuff. Well if the batteries voltage is still low the charging system may go full field so now we are putting 45-60 amps thru a system that was designed for 35 amps max. Now after 55 years lets assume (I still know) we have some corrosion somewhere in the system. So now this spot is getting hot and hotter. Now how many times in 55 years has this happened? So if we repair it the same way it was built and not check every wire and connection in the vehicle and not have a fully charged battery in it and install a 35 amp alt. are we back to square 1 or 36? So at this point of where there is this much damage why not do a couple simple refinements. First why not take a partial or complete load off the amp gauge and associate wiring. It's a extremely simple job. Then lets take some more load off it and provide full voltage to the headlights, again a extremely simple job and both mods are cheap. Now we add a voltmeter to monitor the charging system and a new fully charge battery. So now if that 50-60 amp alt. goes to full field for a little while it's no harm no foul. Now every car show you attend lets look at that bulkhead connector and see how many look melted. It's fun. Sincerely, LO23M8B. ps what is JMO I'm an old guy?
- Joined
- Jan 8, 2012
- Messages
- 7,098
- Reaction score
- 4,247
Very Good points!
This is why I preach updated harnesses! It is only worse when the facts you stated are on 50 year old systems! When I say updated I mean 100%. No short cuts! In other words don’t replace the under hood and think you are fine! Replace it all! Stock type is fine if you are doing stock. You want a 500 watt amp for tunes not fine! Be smart and consider the needs!
This is why I preach updated harnesses! It is only worse when the facts you stated are on 50 year old systems! When I say updated I mean 100%. No short cuts! In other words don’t replace the under hood and think you are fine! Replace it all! Stock type is fine if you are doing stock. You want a 500 watt amp for tunes not fine! Be smart and consider the needs!
- Joined
- Jan 8, 2012
- Messages
- 7,098
- Reaction score
- 4,247
What I could not buy over the counter, I sent to M&H and they made me new plug and play units! This in my case was pure stock and may not work for all, I do sleep at night and drive with confidence knowing 100% is less than 6 years old now.
Auto
First why not take a partial or complete load off the amp gauge and associate wiring. It's a extremely simple job.
Are you suggesting a volt meter, and just bypass the original gauge? MIght you have a link to that theread?
Actually I was the one who said you don't have to, assuming everything is stock, and was about the ammeter, not the wiring.
The reasons with respect to the ammeter are:
a. It shouldn't be under much load. And it most certainly should not be under constant high load. If the needle pegs 40 amps, there is a problem. If it stays there or even near there, there is a big problem.
b. The ammeter is a useful tool. It reveals how much the battery is charging or discharging.
c. Many people think its something akin to an exploding device, hack their wiring, and make more problems than ever were there with the stock system. For Joe average with limited skils and tools its worth assessing whether its needed, especially if they are not willing to invest in doing well.
d. In your situation, the evidence we've seen so far is that there was a short to ground. This is something an ammeter in fact would show that a voltmeter would not. There's advantages to both instruments.
If you want to reroute the alternator and/or battery feeds, that's up to you. Done well, it will result in less resistance to flow, which is a good thing.
If you want to eliminate the ammeter, that also is up to you. I encourage you to install a voltmeter on a switched circuit if you do that.
Whatever you choose for rewiring, it would be prudent to:
First check for ground short in the main circuit - including the alternator.
Second, incorporate a fusible link on the battery feed.
Last edited:
I'm sorry I asked the trans. question on the wrong tread. But as far as taking some of the load off there is no thread that I know of. Personal and professional knowledge. I've been doing it this way on my cars since about 69 when my first amp gauge burned out. Also I've been doing this on all my friends Mopars and past customer cars for about the same time frame. Never had one issue. But this goes along with a couple of other simple mods. If you would like to know just pm me. I'm just getting too old for all the drama. But I am more than happy to help out.
If you want to reroute the alternator and/or battery feeds, that's up to you. Done well, it will result in less resistance to flow, which is a good thing.
You are referring to the battery feed going through disconnect and to ammeter?
If you want to eliminate the ammeter, that also is up to you. I encourage you to install a voltmeter on a switched circuit if you do that.
How would you wire a v meter and have ammeter? In series?
Whatever you choose for rewiring, it would be prudent to:
First check for ground short in the main circuit - including the alternator.
So you're saying a ground short inside alternator could have caused the fire? Interesting, but the wire from alt to firewall , while melted up near disconnect, was OK close to alternator.
Second, incorporate a fusible link on the battery feed.[/QUOTE]
You are referring to the battery feed going through disconnect and to ammeter?
If you want to eliminate the ammeter, that also is up to you. I encourage you to install a voltmeter on a switched circuit if you do that.
How would you wire a v meter and have ammeter? In series?
Whatever you choose for rewiring, it would be prudent to:
First check for ground short in the main circuit - including the alternator.
So you're saying a ground short inside alternator could have caused the fire? Interesting, but the wire from alt to firewall , while melted up near disconnect, was OK close to alternator.
Second, incorporate a fusible link on the battery feed.[/QUOTE]
Look at the link I posted earlier.
Remember current remains the same no matter how many obstiicles in the path.
The heat is created at the resistance locations where current is flowing through.
So when you see heat damage, it means there was resistance to current.
Look at webpage with its illustrations.
I'll be back later and can spend more time then.
Remember current remains the same no matter how many obstiicles in the path.
The heat is created at the resistance locations where current is flowing through.
So when you see heat damage, it means there was resistance to current.
Look at webpage with its illustrations.
I'll be back later and can spend more time then.
OK. I'm back before you.
Here's the page to look at http://www.heritech.org/cuda/Charge2.html
Notice in the examples that heat damage is expected at every connection along the path current flowed.
An analogy to current is air flow or even water flow in a pipe. So its like gallons per minute. The battery is like a pressurized tank and the alternator is like a compressor or pump. Volts is like the pressure in the tank or developed by the compressor.
This gets to your question
There are two power sources in the car, and each has an output wire that feeds the other circuits.
On your car, and most but not all A-bodies, the alternator and battery feeds are joined at splice under the dash.
Wires feeding the various circuits are also welded into this splice.
One to the key switch, another to the fusebox, and a third to the headlight switch.
Here's a couple pics of the ammeter for a 'rally dash'. The metal studs are pressed into the plate and then protected by a
big insulator.
A voltmeter measures the difference in votlage (pressure) between a location in the circuit and ground. It is a high resistance device, but there is a tiny amount of current that flows through it.
It could be wired in like this
But as a permanent setup, that would be a long term problem as you might observe.
It would be on all the time, and so be a slow drain on the battery when the engine isn't running.
Better to wire it in on a switched circuit.
Here's the page to look at http://www.heritech.org/cuda/Charge2.html
Notice in the examples that heat damage is expected at every connection along the path current flowed.
An analogy to current is air flow or even water flow in a pipe. So its like gallons per minute. The battery is like a pressurized tank and the alternator is like a compressor or pump. Volts is like the pressure in the tank or developed by the compressor.
This gets to your question
When I referred to battery and alternator feeds, I am referring to both wires supplying power to the electrical system.
There are two power sources in the car, and each has an output wire that feeds the other circuits.
On your car, and most but not all A-bodies, the alternator and battery feeds are joined at splice under the dash.
Wires feeding the various circuits are also welded into this splice.
One to the key switch, another to the fusebox, and a third to the headlight switch.
Not at all. These ammeters work by having an electric current moving the needle by the magnetic force. The current moves through a metal plate directly in the flow path. So most ammeters, whether its factory or aftermarket, are in the circuit as shown above.
Here's a couple pics of the ammeter for a 'rally dash'. The metal studs are pressed into the plate and then protected by a
big insulator.
A voltmeter measures the difference in votlage (pressure) between a location in the circuit and ground. It is a high resistance device, but there is a tiny amount of current that flows through it.
It could be wired in like this
But as a permanent setup, that would be a long term problem as you might observe.
It would be on all the time, and so be a slow drain on the battery when the engine isn't running.
Better to wire it in on a switched circuit.
Having neither an ammeter or a voltmeter really leaves the driver blind as to the electrical system condition. That's why I suggest installing a voltmeter if you remove the ammeter from the circuit.
Each provides a enough information to generally clue the driver or mechanic in. Some examples:
In the above drawing the voltmeter tells us the system is at battery voltage. If the engine is off, that's normal.
Also in the above drawing, the ammeter is centered. If the engine is off, that's normal.
In the next drawing, the engine is running and the voltmeter indicates system is around 14 V. That's normal.
We can assume the battery is charged or charging, but we don't know which from the voltmeter.
The ammeter shows us the battery is charged and that the alternator is working.
If the battery was charging, the ammeter would show us that. In this next illustration, the meter shows the battery is taking about 5 amps of charging.
Each provides a enough information to generally clue the driver or mechanic in. Some examples:
In the above drawing the voltmeter tells us the system is at battery voltage. If the engine is off, that's normal.
Also in the above drawing, the ammeter is centered. If the engine is off, that's normal.
In the next drawing, the engine is running and the voltmeter indicates system is around 14 V. That's normal.
We can assume the battery is charged or charging, but we don't know which from the voltmeter.
The ammeter shows us the battery is charged and that the alternator is working.
If the battery was charging, the ammeter would show us that. In this next illustration, the meter shows the battery is taking about 5 amps of charging.
Last edited:
One last example.
Engine running, foot on brake pedal.
Ammeter shows discharge. Therefore the system is running on battery power.
Voltmeter is around 12 V. Therefore we know the system is running on battery.
In this case either gage alone provides information that allows us to conclude the same thing. For some reason the alternator is not producing power above battery voltage.
Neither reveals that there is no current flowing to the rotor. That will require diagnoses.
Engine running, foot on brake pedal.
Ammeter shows discharge. Therefore the system is running on battery power.
Voltmeter is around 12 V. Therefore we know the system is running on battery.
In this case either gage alone provides information that allows us to conclude the same thing. For some reason the alternator is not producing power above battery voltage.
Neither reveals that there is no current flowing to the rotor. That will require diagnoses.
flingdingo
Well-Known Member
Hey Mattax, what program are you using to draw those diagrams?
A combination of IrfanView and MS Paint. Paint is better for moving things around but is limited in line widths and rotation angles.
IrfanView also has a screen capture which works pretty well.
I'd like to make a few gifs with the arrows in motion but never get around to it. That would better convey the idea of the electricty flowing.
Of course the guys who remember their electric studies will then point out that the electrons flow the other way. LOL.
Re. Heritech.org, diagram 3, "the short is in the output circuit of the alternator"
the ignition would have to be on for this to allow current flow/fire? The wiring closest to alternator is not burned, so I'm assuming ign needs to be on.
I never knew that while running, there are times when only alternator current is energizing everything. I always see the ammeter ga. slightly to the right of center.
I've been looking for the ammeter/alt/headlight/fuse intersection but never found it. Maybe now that all the insulation is gone, I'll see it.
THanks so much!!
the ignition would have to be on for this to allow current flow/fire? The wiring closest to alternator is not burned, so I'm assuming ign needs to be on.
I never knew that while running, there are times when only alternator current is energizing everything. I always see the ammeter ga. slightly to the right of center.
I've been looking for the ammeter/alt/headlight/fuse intersection but never found it. Maybe now that all the insulation is gone, I'll see it.
THanks so much!!
Last edited:
to the OP: so my understanding is that your insurance company is doing the right thing. If that's the case, why are you working around a 55 year old wiring harness, or contemplating buying a used 55 year old harness to put back in. M&H make exact direct replacement dash harnesses for 64 and 65 Darts an Valiants. They are sold through Year One. yeah they cost a bunch ($450?). Ask the insurance company to replace the burned up harness and then make an investment and buy the underhood harness to go with it. Then you have new wiring throughout, no compromised connectors, wire insulation that is new and pliable, new bulkhead connectors that can be packed with di-electric grease while new. IMHO this is a good investment and a cheap insurance policy compared to patching stuff together until the next piece of 55 year old wiring burns the car up for good. The original wiring lasted 55 years, if this new wiring lasts half that long it was worth doing.
If all the cable wrap is removed, you can follow any of surviving wires to it. Most of us never have to dig in that deep.
Str12's suggestion is probably the best. M&H stuff is pretty good and getting the charred stuff out of the car will go a long way toward disappating the odors. Once all the burned material is out, look into whether an ionizer will speed the process of removing the smell. Sometimes those are put in a house after a smokey fire. So maybe it applies to cars as well.
No. The alternator feed is always hot. With everything off there is still a connection to the battery positive. Using the pressure analogy, its like have 125 psi in all the lines.
If you don't mind, lets use the diagram above. But if its not as clear we can go to the other one.
All of these wires are at battery voltage. Lets call it 12.8V
There's no current flowing.
The 12.8 Volts is like having 128 psi in the water pipes in your house or air supply in a shop with all the valves shut.
Current is like the flow of the water or air if one valve is opened, say an air wrench running, or sink faucet opened.
That's the way it should work.
But if the valve is broken off or the piping cut, the entire reserve tank is going to empty out.
Clearly the ignition was off in your case. The burning is not caused by the current alone. Its caused by the current flowing through a resistance.
The alternator is not burned, but there could be a good short inside. If not, then there must have been a short in the wire.
The burned cable shows us that electricity passed through there and it met a lot of resistance at that location. Perhaps the short was right there.
You're not the first. At one time me too. And rest assured many others too. The alternator is the higher voltage source, so electricity always flows from the high voltage to a lower voltage.
You can use the pressure analogy here too picture the flow from a pump that normally produces at higher pressure than is in a reserve tank.
Demonic
Well-Known Member
It's the first thing I buy for all my vehicles. The AACA requires a fire extinguisher for most judged cars. A small or medium one is not expensive at most stores. Every car guy should have one in each of their cars at least.
Yes, absolutely. As a guy who has done control and high voltage wiring professionally, as well as parted out plenty of Mopars back in the 80-90's, I'll say this: I have cut apart and modified a few 40-50 yr old harnesses. When you unwrap a wire 8" back and strip the insulation and the copper is not bright, but already brown from slight oxidation, you are fighting an uphill battle. Wait for a YO 20% off sale and buy the M&H harness. If you're handy w electrical, and well versed in wire size and current carrying capacity, loads, current draw for DC, measuring resistance, etc, buy wire and build your own.
If its that way all the time then that is zero. The one in my jeep is like that, not perfectly centered.
If it moved that way when the engine was running, then it was charging the battery.
-
