MTFCA Forum

Late yesterday afternoon, four of us went for a ride in my ’27 Touring. After about 20 miles, we drove into a COE park to see the numerous deer there. I stopped at the gate and as the gate keeper was interested in the car, we started talking. I shut down the engine. It was running on mag. When I tried to restart it on battery, everything was dead. I tried to crank it on both battery and mag.
I tried for about a half hour to figure out what went wrong and finally called Hagerty and got the car flat bedded to our house about 8 miles away. When I got home it still wouldn’t start. I the checked the 7-month old 6-volt battery and it only had 4.7 volts. I charged the battery for around 14 hours until it was fully charged. Then I load tested it and the tester showed that the battery was good. Then the car started easily and ran on mag. The ammeter showed charging at about 3 amps.
I’ve owned this car for over 30 years and never had a problem like this. What could have happened that could cause a battery to completely discharge while running on mag?

When running on mag, how many amps is the generator charging?

Thanks for your replies but I think that I have figured out the problem.
The battery is about 7 months old. The ammeter showed charging at 3-amps before and after the incident. All the battery and ground connections are good. It has a diode type cutout.
The battery hold-down clamp near the positive battery post was a little loose. We had driven on about a half mile of rough gravel road and I think that the battery jiggled enough to short it out.
The battery seems to holding a charge now but I’ll check it again in about a week.
Thanks again, Robert

Check to see if your generator charge is gettin to the battery ussing a volt/ohlm meter. Check the cable and the battery post. As mentioned, the problem could be corrosion between the battery post and the cable connectors.