Smoke....Hot Battery. Close Call.... Voltage Regulator Problem?

[Skull-1]

So I was idling the Charger (1969) in the driveway as the weather hasn't been good for driving.   Had the Emergency Brake on and the associated Brake System light illuminated.

After I got the car up to operating temp I let it sit a bit longer still running and got in to pull into the garage.

As I pressed the gas pedal to see what my tach was doing the Brake System light went out and the car died.   I saw some smoke wisping from the dash.   I then turned the disconnect switch off on the battery and held my breath.

I heard the battery sizzling and it was hot to the touch.   Thankfully it is an Optima so there won't be acid running all over.

Obviously something is hosed up.  Maybe a bad voltage regulator? Any thoughts on what to look for beyond the obvious?

Will take the dash out and see what smoked.  Very scary....

[Pete in NH]

Wow! Close call for sure. As you said, the voltage regulator is the most likely suspect. It sounds like the alternator output went wide open, which could be around 17-18 volts. The smoke under the dash is likely a fried ammeter from a very high current event. On a 69 you should have a fusible link from one of the bulk head connector pins to the 5/16" battery terminal on the starter relay. That link may have also burnt open as it is designed to do. It should be a blue 16 gauge wire and may have a small molded tag on it saying something like -link or fuse.

Just so I understand the whole picture, what alternator do you have on the car? 69 was the last year for the single field wire alternator and old electromechanical regulator. Many got converted to the newer two field wire alternator and electronic regulator. Do you have a test meter you can make voltage measurements with?

[JamieZ]

Mine did something similar, it was the voltage regulator.  Overcharging the battery....mine fried the new tach I had just put in the car   Hope your fix is less expensive.

[68charger440]

So I was idling the Charger (1969) in the driveway as the weather hasn't been good for driving.   Had the Emergency Brake on and the associated Brake System light illuminated.

After I got the car up to operating temp I let it sit a bit longer still running and got in to pull into the garage.

As I pressed the gas pedal to see what my tach was doing the Brake System light went out and the car died.   I saw some smoke wisping from the dash.   I then turned the disconnect switch off on the battery and held my breath.

I heard the battery sizzling and it was hot to the touch.   Thankfully it is an Optima so there won't be acid running all over.

Obviously something is hosed up.  Maybe a bad voltage regulator? Any thoughts on what to look for beyond the obvious?

Will take the dash out and see what smoked.  Very scary....

i had that happen also many years ago and have been chasing electrical gremlins ever since.  In my case it was the bulkhead connections going to and from the ammeter.   I would strongly suggest you perform the ammeter bypass or at least feed the ammeter without going through the bulkhead connectors like ma Mopar did on the cop cars back in the day.  it was a known problem even back then.  I would also convert to the 70,s digital regulator setup.

[Skull-1]

Wow! Close call for sure. As you said, the voltage regulator is the most likely suspect. It sounds like the alternator output went wide open, which could be around 17-18 volts. The smoke under the dash is likely a fried ammeter from a very high current event. On a 69 you should have a fusible link from one of the bulk head connector pins to the 5/16" battery terminal on the starter relay. That link may have also burnt open as it is designed to do. It should be a blue 16 gauge wire and may have a small molded tag on it saying something like -link or fuse.

Just so I understand the whole picture, what alternator do you have on the car? 69 was the last year for the single field wire alternator and old electromechanical regulator. Many got converted to the newer two field wire alternator and electronic regulator. Do you have a test meter you can make voltage measurements with?

I have had a fusible link go out before but that was YEARS ago.   It can be unnoticeable externally, correct?

I will have to check on the alternator.   The engine was rebuilt a couple of years back and now I am wondering if they swapped alternators and/or VRs on me.

1) How do I tell if it is a dual-field vs. single-field?
2) If I have the correct alternator but say a 1980 voltage regulator from another 318-engined vehicle will that cause the problem?
3) Could it be my old-style VR died and caused the problem?
4) Does the brake light being on mean that was where the greater-than-12-volt draw was?

I have new Year One Engine and Dash harnesses in the car so I am hoping the wiring itself wasn't the problem.

Mine did something similar, it was the voltage regulator.  Overcharging the battery....mine fried the new tach I had just put in the car  Hope your fix is less expensive.

The battery was so hot I couldn't believe it.

i had that happen also many years ago and have been chasing electrical gremlins ever since.  In my case it was the bulkhead connections going to and from the ammeter.   I would strongly suggest you perform the ammeter bypass or at least feed the ammeter without going through the bulkhead connectors like ma Mopar did on the cop cars back in the day.  it was a known problem even back then.  I would also convert to the 70,s digital regulator setup.

I will have to pick all of your brains on what I need to modify to fix this.   Sounds like: 1) Conversion for Dual-Field ALT, 2) Modern VR, and 3) Ammeter Mod/Bypass.

I sure hope I can find a good electrician as I am pretty inept in that department.

Thanks all.

[Pete in NH]

Hi,

I would disconnect the negative battery terminal and leave it off until things get fixed. I would connect it only when working on the electrical system for tests.

I would also take the battery out of the car and carefully inspect it. I'm not sure how those Optima batteries are vented. That battery took a really bad beating and may have been damaged. It very likely outgassed at a very high rate and if those gasses were not vented off the battery case may have been damaged. Look for swelling, bulges etc. Put a voltmeter across the battery and it should read around 12.6 volts. If it is less, something like 10.4 volts a cell was likely shorted. If the voltage looks good, take the battery down to the local auto parts place and have them put a load tester on it. If it passes you can put it back in the car.

1- fusible links can melt under the insulation often you can not visually see it has melted so it needs to be checked with a voltmeter. You should have voltage at both ends of the link . You can also use an ohm meter and check for continuity.
2- Chrysler used the electronic regulator well into the 80's on trucks. The electronic regulator is a squarish box about 4 or so inches square with a triangle shaped connector on the lower front.
3- we still need to figure out exactly what alternator/ regulator system you have on your car. The alternator will have three wires coming off it if it is the two field wire electronic system and only two wires if it is the old system. If you are still in doubt post some pictures of the alternator and regulator.
4- The brake light on doesn't tell you anything about the charging system.

I would carefully inspect all your new wiring harnesses from the alternator output stud to the bulk head connector, to the ammeter and back to the bulk head connector for signs of melted insulation both the wrapping tape and wire insulation. Also, carefully check the ammeter studs and the insulation around them. Also, unplug the bulk head connectors and look for signs of melted plastic or burnt connector pins.

Once we figure out what alternator/ regulator system you have, we can think about what needs to be done to repair things and do some upgrades.

[GPULLER]

E-brake lamp burned out because of 18V the alt was putting out?

[Skull-1]

E-brake lamp burned out because of 18V the alt was putting out?

It didn't burn out but went out when the car died completely.   I am hoping the fusible link went before any damage occurred.


Pete in NH I will get back to you here when I have all the info.  Thanks in advance.