loudhvx wrote:
The most common cause is wiring errors or breakage.
The next main problem, on the 77, is the regulator. Next would probably be the rectifier. Next would be the stator, next would be the field-coil.
I agree, except I would check the field coil first, if the field coil doesn´t get power or has an open/short the alternator won´t work.
The wire connected to the green lug on the regulator feeds/controls the field coil - check that it´s not broken and that all connections are good/not corroded. To check the field coil, disconnect the wire that connects to the green lug on the regulator and measure resistance between this wire and the frame (ground) - you should see like 2.7 - 3.4 ohms, any more and the field coil has an open in it, any less and it has a short, in both cases it should be replaced.
That 77 alternator is a very expensive design, and is pretty good, but the mechanical regulator usually has weather/environment related problems.
Good news is that the regulator can be opened and cleaned/adjusted - I´m not at home right now, so I don´t have access to my files, but the procedure is described in the manual. Basically the 77 regulator consists of a coil and a set of breaker points, the manual describes how to clean the points and adjust the gap.
Post edited by: OnkelB, at: 2007/02/06 15:29