I have the diagram here and it shows 2 15A fuses, one for the charging circuit, the other feeds the electronic and speed control, it has been 2 1/2 years since I was inside my grey box but I think the electronic ignition would be less than 15 - maybe a misprint in my book? Red is the wire color shown to both fuses on the battery side and red goes onward to the rectifier block, yellow/red goes towards the multi-purpose electronics block that has a total of 6 wires involving the guages-buzzer-lanyard switch and the rectifier block has only 4 - this may seem vague and risky, if you know the charging is working try a 7.5 fuse but do not go past this to 10 amps or more damage could result.