Discuss all things Model T related.
- Posts: 152
- Joined: Mon Jan 07, 2019 9:09 pm
- First Name: Dennis
- Last Name: Fleming
- Location: Luray
- MTFCA Number: 27815
- MTFCI Number: 19314
- Board Member Since: 2005
I have a generator that pegs the amp meter while running fast idle and after a few minutes run time the commutator starts to get hot and smoke. Took the brush cover off and while running there are sparks running around the commutator from the brushes. Wiring is correct and when a load is put on ,the amp meter discharges while not running.
- Posts: 103
- Joined: Sun Jan 06, 2019 6:57 pm
- First Name: John
- Last Name: Hunter
- Location: Blue Mountains, Australia
- Board Member Since: 2002
The charge current would appear to be excessive. Try changing the position of the 3rd brush to reduce it down to about 5A. If that doesn't work, the next thing I'd do is check the position of the brush plate. That entails removing the generator from the engine and connecting it to a battery so it runs as a motor. The third brush is lifted off the commutator and the brush plate is rotated to its null point; i.e. the generator stops spinning in one direction or the other. Then it can be put back in the car and the third brush set in the usual way. Be aware that many original brush plates crumble apart if the nut securing the 3rd brush has been tightened excessively. When that happens, the 3rd brush becomes grounded and it won't charge.There's a good fibreglass repro if it needs replacement.