Bow thruster problems

[galeus]

My Sidepower 3KW 4,1 HP bowthruster had blown a fuse (80A) and I replaced it with a 100A fuse from ASAP which seemed good value at about £5. In no time that had blown as well and I now think it was not a slow blow fuse (I'm guessing a bit here as the original 80A had a ceramic bit covering the blow bit and the cheapie was more like plastic.
Both fuses looked like they had burnt out and the previous week the boat had been out and we had checked the free movement of the thruster prop.
My mech.friend has advised me to replace the fuse and he will check the current draw in location, but suspects motor problems.
He has advised me to get 4 motor brushes before he gets further involved.
Has anybody any advice on sourcing brushes other than sidepower as they seem a heck of a price.
I have seen this site http://www.bargainbrushes.com/
Any thoughts please.

 

[Seastoke]

if you had sizes any motor rewind shop can get them made ,but if the brushes are caput you will see ,take the cover off and try the thruster sparks will fly if motor caput ,unless it is solid ,is your battery ok as low voltage high current