Charging Alarm

[PRH]

Boat new to me, Stbd charge voltage has always looked low and was picked up in the survey. Alternator output checked and was 13.? (9 I think), the same voltage as Port alternator.

Engines are 63Ps.

Last two times out the charge light has come on with the accompanying alarm which quite rightly gets the attention deserved.

I now feel I have to investigate further and will of course start with the alternator first but thought it worthy of a quick post on here to see if anyone would have any suggestions as to the best course of investigation…..?

TIA
Peter

 

[powerskipper]

have you checked the belts, it could be slipping when warm.

 

[P4Paul]

I agree with Power Skipper, check the belts. It might also be the Alternator bearings getting tight when warm, or the belts becoming polished. If the belts are at the correct tension, rub some talculm powder on them and see if that helps. If no improvement after dressing the belts, purchase a service exchange alternator.

Or alternatively, sell the MoBo and buy a proper vessel with sticks, strings and sails........

 

[halcyon]

Starboard will allways be lower, it supplies the domestic power, and has to recharge the battery.

You could have a diode or regulator in the alternater that is failing when it gets hot. You need to check battery voltages when you start, and after the light comes on. Checking the voltage on the alternater output pin would be good, but may not be safe.

If you are droping volts, and the belts are ok, get the auto elect firm to check alternator hot. If you do not tell them, they test cold and it would appear ok.

The ammeter is showing net amps into the battery, not alternater output.

But voltages are your first port of call.

Brian

 

[Talulah]

Had a similar issue. Dismantled the alternator. Found one carbon brush much longer than the other one. Conclusion was that the longer brush was barely touching the contacts as it was not getting pushed into place by the spring. Got worse over time as less and less made contact.

 

[LittleShip]

Steady on Julie that was a technical post!
/forums/images/graemlins/smile.gif

Tom

 

[PRH]

Thanks for the info all.

Talulah did you get a new brush and if so where from?

Peter

 

[STEVEDUNSTABLE]

Or alternatively, sell the MoBo and buy a proper vessel with sticks, strings and sails........

[/ QUOTE ])now that really is below the belt !!!!!!!

 

[powerskipper]

er sorry, must have had a brain storm /forums/images/graemlins/laugh.gif

 

[Talulah]

I was able to just free up the brush by pushing it back and forth on its spring. It was fine after that.