Alternator died. Cause? motor ran w/batt off?

[David M]

Originally Posted by RaptorDance

Xantrex and a number of other companies make them. Check at your nearby Chadlery. They should be under $40.

These are a great idea. All they are is a high voltage diode that keeps the voltage spike caused by the field collapse from feeding back The markup on them must be incredible...still worth it though.

[David M]

double post..sorry

[senormechanico]

For those of you who want to save some bucks on a "zap stop" diode, go to your local electronic supply store and buy a Zener diode rated at 17 volts and 2 amps or above.
Hook the cathode end (usually marked by a band) to the BAT (+) terminal on the alternator. Connect the other end to battery (-).

You'll probably only have to spend about ten bucks.

Steve B.

[hellosailor]

David-
After uncovering a dead Zap Stop (improperly mounted in electrical tape, vibration had broken both leads off it) in a friend's boat, I went looking into them. You CAN indeed buy the same type and rating of diode for about three bucks from a parts place, quantity one, if you know where to order what. Typically plus $5 shipping and handling if that's the only thing, so we're up to eight or ten bucks.
Which also makes it not unreasonable that the same thing sells for $25 on the chandlery shelf, marked up by a wholesaler and retailer with instructions and bits of shrink wrap, etc. for a sailor.