Mira este enlace y los links que dan.
http://www.oldmarineengine.com/discu.../5/132669.html
Dynastart system tests.
Remove belt.
Connect bulb or voltmeter from D+ to earth.
Disconnect DF lead.
Operate start control, motor should spin and 12V appear on voltmeter (or bulb light). Lack of reading or lamp indicates supply fault, failure to spin when supply is present indicates motor fault.
With motor spinning, earth DF terminal. Motor should abruptly slow with momentary increase of voltage or bulb brightness. Failure of either indicates motor fault.
Reconnect DF at motor and re try both tests at the regulator end. (Lamp/meter on regulator D+ terminal and disconnecting regulator DF) Failure indicates wiring fault.
Common dynastart failure is in the field coils, there should be a resistance of 4-6 ohms between D+ and DF on the unit with wiring disconnected.