Alternator problem

[Ziffius]

So I fitted a Sterling Pro D advanced regulator a few months ago which involved a bitter of soldering of wires to the top of the the brushes. No problems until leaving fuel dock to go into marina last month when the battery alarm sound and no charging is indicated on the battery monitor.
Once docked I tried unplugging the advanced regulator but to no avail and then found after a few starts it was working again.
Back to the boat this month and no problems for a week then last night again battery alarm and no charge. Checked all the wires and tried discount the advanced reg but no joy. Pulled up anchor today after an unusual thunderstorm in Greece and sailed back to marina - wind was right direction and plenty of most of way!! Had to run engine about an hour out from Marina and put ear plugs in to cancel out battery alarm - after 40 mins just before entering Marina the battery alarm stops and full charge is on - agggggh.

So going to get the experts in tomorrow to see if they can figure what's up, anyone had this sort of problem??
The only suspicious thing I found when I removed the regulator (valeo yv7726) off the altwrnator was that one brush contact point was blacker than the other on the 'rotor'?
Tried giving it a clean before reassembly but did look much different. Now it's working again I have a feelin the experts will be scratching their heads aswell!

[IslandAlchemy]

Bad earth wire connection

[Odysseus]

Alternators get a lot of stick, but they are very reliable in general, however depending on the design you will have a brush box at the end on the shaft or rings pushed over the shaft, these carry the brushes to the commutator for the want of a better word.
The brushes movements to contact the power source must be free in and out of the holder, sticking brushes are a well known fault.

As you have interfered with this area when fitting you smart charger I would revisit this and check.  One of  the quick checks we did in production of alternators when this happened was "wack the area near the brush holders" this was a controled wack not a 5lb hammer. If this sorted the issue we stripped out the brush box.

The other thing is alternators are not designed to be fitted with after market smart chargers,  look in the small print of your smart charger, they opt out of all responsibility for their wrecking of the alternators. I have said this before on this forum, put you hand on the running alternator fitted with a smart charger under load, its well over the optimum safe running temperature. Fit a property designed one.

Hope this helps

Odysseus
Bav 38

[Ziffius]

Tech took it away and recons sterling reg isn't working and had to change the windings of the alternator. Took the boat out but after a few hours  of motoring then at anchor whilst charging batteries the engine starts dieing. Looking again tomorrow.

[landes_h]

Why don't you contact Sterling Power ??
After all it's even a British company.
I refused to fiddle with this Charge Booster and put in my Bav. an A2B charger. Installation was as easy for me as tax fraud for others.
In fact I have a charge booster from Sterling Power still at home for sale (unused, resp. inspected by Sterling).
I did install one on my old Elan 33 with Yanmar engine and Hitachi alternator. Quite a job.
The Sterling A2B charger just replaces the splitter diodes. Same cables, same place....

[Nigel]

I've split this topic, other discussion at Engine runs fine for a few to 10 mins then revs die off

[Ziffius]

In hindsight I wish I had gone for one of this instead