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the "early" Lincolns - 1920 to 1939
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Lincoln "L" Technical Questions

Peculiar electrical problem
Allan Rustad
My 1929 L has recently developed a strange behaviour - the charging rate from the starter-generator has dropped off suddenly, it used to charge minus 3 Amps  at slow idle, then increase to about 15 at full speed, cold. After driving quite a while the thermostatic switch activates, cuts the rate to about 10A at speed.
Now, it charges about 8A at idle, and revving the engine up to get to zero is not a practical idle speed, as gear shifting is difficult.Driving at normal speeds, 35MPH or so, charging max 10A. The other, mysterious thing, is that when parking the car, if the throttle is set to high idle so as to have a slightly positive charge rate, when the ignition switch is turned off, the engine continues to run. Put the throttle down to slow idle, and the engine stops. I can drive the car, but am putting charger on battery when it is home in the garage.
What's going on here? Is the thermostatic switch hanging open? Something goofy with the ignition switch? VERY STRANGE.