Voltage regulator smoking?

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VanPhin

VanPhin

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Hello
I own a 1966 dodge dart, I was driving it with an friend when the alternator gauge was all the way at charging you couldn’t even see the needle but when I stopped at lights it would go back to normal. I got up to 50 when smoke started to come up from behind my gauge cluster I quickly pulled over to the side of the road and looked under my dash it smelled like burning electronics. I called my dad and he told me to pull forward if possible to a safer spot so I did the car started right up and I pulled forward but when my dad got there to help me the car was completely dead non of the lights came on, nothing worked. My dad said it was the voltage regulator but I’m not to sure I’m 16 and a bit under experienced any advice?

0C8C911C-161A-4EC6-8D5A-24275376066B.jpeg
 
Stuck voltage regulator, charging at 17 or more volts. Next time you see that turn engine off as soon as safely possible. Do not keep driving. Now unplug regulator then you can keep driving.
 
I’m not an expert, but the very same thing recently happened to me in a ‘67 barracuda. Round back alternator, and the mechanical voltage regulator. I think that regulator failed, making the alternator overcharge the battery at 17-18 Volts and that fried the main power wires at the bulk head connector. Melted the plug. I was dead in the water after that.

I fixed the bulkhead and put a new mechanical voltage regulator and it seems to be okay. For now. The one I got from summit, has Made in the USA stamped on the back of it. How accurate that is I do not know.

Standard Motor Products VR-101 Standard Motor Voltage Regulators | Summit Racing

There are other fixes I did with the electrical but I will let others post who are smarter than me.

@67Dart273
 
Thank you for this info
I looked a little closer at all the wires and I’m beginning to doubt that it’s the voltage regulator itself since the smoke was coming straight out of the gauge cluster and the voltage regulator is on the other side of the fire wall but the regulator could be overcharging or something like that plus there is a after market radio and the wires are older than the Nixon administration and very unorganized I’ll send some photos thank you for all of your help
 
The voltage regulator failed, and what you have in the gauge cluster is an ammeter, not a voltmeter. The way it's wired the full current from the alternator goes through the bulkhead connector and through the ammeter. With the voltage regulator failure, the alternator output went straight into your under dash wiring, so, more then likely you've melted some of your under dash wiring.

Trace the wiring from the ammeter under the dash back to the bulkhead connector and then the other direction into the dash harness. You'll likely find something in that path that's melted.

It looks like there's been quite a few modifications to your wire harness over the years, which isn't uncommon at all. These cars didn't have all that many circuits when they were built (didn't need them). Unfortunately it's probably time to look into a new wire harness, because even if you find some of the melted wiring that caused the smoke and electrical smell there's probably more of the harness damaged than that.

It doesn't look like @67Dart273 has chimed in yet, he's one of our resident electrical experts and he may have some more specific advice for you on things to check. I'm not particularly great with electrical stuff and I don't know the early A's as well as the 70+ stuff.
 
Good suggestions. These cars all pretty much had what is called a "fuse link" which is darn poor protection, but it may have finally blown.

Maybe you learned a lesson. At signs of trouble like this, stop and find out "whut." I know you don't know, but you could have disabled the charging system simply by pulling the "push on" connector off the VR or the green wire field connection at the alternator.

You have likely damaged some wiring. You are likely going to have to get into the dash, pull out the harness, unwrap them and examine for melt damage. it is common in such cases, for wiring to heat up and melt the insulation inside a harness and cross the wires inside together.

You are for sure going to need a factory service manual and wiring diagram
 
The voltage regulator is the metal box to the right of the master cylinder, with two wires, one on each end. It looks like you're still using the original mechanical picture.
 
I think what I’m going to do is order a new regulator and go through the wiring thank you guys for all the help

IMG_3145.jpeg
 
A couple of suggestions when you are fixing this. I believe yours is a 1966 Dart? That means the wiring is almost 60 years old. The manufacturer never thought it would still be on the road in 20 years, let alone 60. Yoru under dash pictures show a lot of repairs from over the years, But I don't see burned, melted or toasted wires. you need to find the two fattest wires that come from your firewall, one red and one black and trace them under the dash looking for heat damage.

If you are going to keep the car for a long time and depend on it to get you where you are going, I would invest in a new wiring harness, There are companies that make complete factory correct wiring and that would clean up all the various repairs under your dash. This isn't cheap - be ready of sticker shock, but it and the brakes should be your first order of business in fixing your car up.

I don't have an early A-body, but I think that you can update your voltage regulator in kind with a transistorized model. Chrysler stopped using the type you have in the late 1960s. Somebody with an early A please provide better info.

You did just the right thing in your post by supplying lots of pictures!
 
Somebody else look at his firewall/wiring photo. I don't see a fat red wire and a fusible link headed for his bulkhead connector - did somebody already bypass his bulkhead connector?
 
well, i think you know this but it bears repeating: you're supposed to keep the smoke inside the wires.

all kidding aside, the best thing to do at this point is take apart the dash and see how extensive the damage is. take this opportunity to upgrade, repair and replace stuff. and clean up that spaghetti farm you've got going on.

clean and tidy wiring is key to keeping something safe and reliable. electrical fires are no joke and it'll smoke a car faster than you can imagine.
 
I really like your Dart! One of the first cars I remember riding in was a 65 Dart 270 that was our family car when I was 9-14 years old.
 
I too question whether or not the regulator itself failed; but lets call that possibility one.
We see some wiring modifications in your photos, so lets also see some photos of the alternator - both sides.

I'm sorry this happened to you. Unfortunately there's no clue on the ammeter that when the needle is near either extreme (or beyond) this is a critical situation and needs immediate action.

As mentioned above, the ammeter is located in the battery feed/discharge line.
The needle is moved by electric current flowing past it. Or more specifically the small magnetic field created by that flowing current.
When current is flowing into the battery, the needle points to C for Charging.
When current is flowing out of the battery, the needle points to D for discharging.
The ammeter is calibrated to show 40 amps to 40 amps. The middle (zero) is normal after the battery is finished charging.
Anything over 20 amps for more than a few minutes is going to be a problem for connections, wires, and sometimes the ammeter itself depending on model and condition.

Fortunately the circuit is pretty easy to follow on your '66. Of course we have to figure what the previous owner(s) modified, but the basic circuit is pretty simple.

Now the bad news. When there is no votlage regulation all electric circuits there were on while you were driving saw much higher voltage. Ever notice that lights are brighter when the engine is running? That's because with the engine off they get electricity at 12 volts from the battery. But when the engine is running they get power at 14 Volts from the alternator. So if any lights were on and the alternator was supplying power at 16 or 17 Volts, might have burned them out and/or fuses and connectors may have got hot. So you will want to check all circuit connctions and lamps that were on at the time for signs of heating. This includes the ignition.

Votlage regulator: We see a mechanical regulator in the photos. Take it off, open the cover and take some photos and examine it. if the points are stuck or burned together thats likely the cause. if not, then we need to do some more investigating.
 
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Why is the gage labeled 'Alt' when it really shows current to or from the battery?
If the battery is discharging when driving, then the engine is running on battery and something is wrong with the alternator circuit. Also if the charging increases with rpm like it did in your case, something is wrong with the alternator circuit.
I don't know if that's why they labled it "alternator gage" but its a good way to think about it.
ps.
In the shop manual they call it an ammeter.


I agree with the suggestions to get a factory service manual. The downloads from mymopar are fine.
I'm going to post a simplified diagram but you will learn it the best if you draw or trace your own.


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The solid black circle is a welded junction joining the main circuits.
The alternator output (wire R6) feeds the connected circuits. This includes the battery when it needs recharging.
When the engine is off, or the alternator can't supply power, then the battery supplies power through the same junction.

Really important is to observe that these wires are all connected to the battery positive. In other words they are electrically HOT at all times (unless the battery is disconnected).
Q3 feeds two fuses in the fuse box. Anything connected to them can be turned on at any time (dome light, headlights, etc)
J2 is the run circuit. It feeds both the alternator's rotor and the engine's ignition.
 
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Thank you very much you guys are really knowledgeable on this and I would be lost with out the help you have given me and I will get you guys the photos of the alternator and the inside of the voltage regulator. Luckily no lights were on during the surge in power I will check the fuses and I downloaded the manual and the diagram
 
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