Posted by Sam on February 24, 2004 at 14:30:42:
In Reply to: Strange part posted by SG on 07/22/02 at 11:49 AM:
The black lump could well be a Zap-Stop (West Marine)
Its a Zener Diode that supresses (grounds) voltages above about 25VDC to protect your Alt's diodes if, say, the Battery Master switch is moved while the engine is on.
I have one and it works great.
I also have high performance, Low Vf diodes which can withstand 65VDC spikes, so I can't tell if the Zap-Stop is "saving" my diodes. I CAN switch batteries with no probs on my boat though.
Capt Sam