mastervolt charge regulator fuse blows

[gilligansail]

I have a mastervolt 12v/130 amp alternator which was rebuilt about 3 months ago. The line that goes from the mastervolt alpha MB regulator to the pos terminal of the alternator has an inline 10 amp fuse. This fuse is blowing repeatedly.

The engine will run for a while and the charging system works until the fuse blows again.

I checked all the connections which go to and from the regulator and they all seem good.

What next?

[smac999]

so the power wire that feeds the regulator?

if it's drawing too much power, it's either a bad regulator. or could be the alt if it's drawing too much field current. which doesn't narrow it down at all...

if you have a clamp meter. measure the current on that wire. and also the feild wire.

Ie if you are pulling 10a on the power wire and say 5a on the field. and it's blowing. then it's the reg that is bad. if it's pulling 10a on the power wire and 10a on the field wire. then it's probably the alt that is bad.

could also be something loose that draws normal current for a while, and then shorts and spikes, and blows fuse. you'd have to figure out if its' drawing say 9.8a right from the start and finally fails after time. or say draws 5a for 20 mins then spikes to 10+ and blows.

[gilligansail]

Thanks for the help
I’m getting a new regulator later this week