I have two 3GM30
Yanmars with 55 amp alternators . As part of an electrical
upgrade by PO both alternators were fitted with external voltage regulators. One of the alternators stopped charging
and I went to the hassle of taking the alternator
off and pedalled 90 mins to a marine
elctrician (Oh How I wish I had not sold my car to go cruising
). Electrician tested alternator
on bench belt and found it was OK - WTF!!
I returned to the boat and refitted the alternator & checked the external voltage regulator
. The two green lights were on when I ran the engine
, just like on the other engine
whose alternator was working fine. I did notice that the 15 amp fuse in the wire from the ext regulator
had blown. I replaced it and the alternator worked for a couple of hours but has again stopped BUT the fuse checks as OK this time.
When I get back to the boat in 2 weeks after this work stint is over, I was considering doing the following in order of ease of accomplishment
1. change the fuse anyway (BUT why did it blow in the first place - thoghts, any one??)
2. clean the small contact spade on the back of the alternator where the excitator wire inserts
3. check the current
coming down the excitator wire at the external voltage regulator and at the alternator
4 swap alternators between the engines
Does anyone have any thoughts /ideas / suggestions??