2000 100hp 4 stroke just quit tonight

[sniper]

Took the pontoon boat out tonight and everything was good. Came back in and about 500 yards from the house the boat just cut off. Ignition switch would not function, power trim switch would not work. Gauges were shut down. Kill switch was not activated, battery was fully charged, fuse block fuses were checked and all were operational. Is there a main fuse under the cowl of the engine. Wires under the consul were checked and all were connected. Any ideas what could have happened. No warning and no burning smell involved.

[boats.net]

Need to check fuse on engine probably has a blown fuse, may have something shorted out on engine.
The fuse is number 25 and 26 in this diagram Yamaha Outboard Parts 2000 F100TLRY ELECTRICAL 2 Diagram

[sniper]

found 30 amp fuse blown - still have problem

Thanks for the assistance you gave me about the engine fuses. The 20 amp fuse was good but the 30 amp was blown. Put new fuse in and as I was putting it in it sparked and blew out the new one.

I went under the console and checked for broken, bare or damaged wires. I replaced some wires that looked fair and checked the connections at the ignition switch. I also checked all the connections I could visually inspect under the console. I removed the timing belt cover and checked the wires at the engine for any evidence of the problem. Could not locate the source of the problem. I also removed the leads to the starter and cleaned them off. I disconnected the accessory wire from the battery and still it blew the fuse. I have no idea what to do next. Could it be something inside the ignition switch?

[99yam40]

attach a voltmeter across the blown fuse connectors, you should read full battery voltage if there is something shorted or trying to pull current and then start disconnecting wires until the 12 v battery voltage reading goes away telling you where the problem is located.

[sniper]

May have found problem need your advice

Checked the charging loop and it was definetly being grounded. Started to investigate and when I unplugged the RECTIFER the charging loop was no longer being grounded and the voltage was normal. I was able to engage the starter when the rectifier was not connected and no fuses were being blown.

Is is normal for a rectifier to go bad suddenly without any warning and do they go bad from time to time. What would make one go bad??

Just need info prior to ordering a replacement (electrical parts). Thanks for all your help guys.

[99yam40]

They can and do go bad from time to time, but I do not know what would cause it.
Maybe stater problem,or charging full out for too long and over heating? Electronics go bad
You may need to do some more research on that and let us know what you find out

[sniper]

Resolved the issue

I ordered a new rectifier and within an hour I was back on the water. The motor is running "SWEET" and all is good.

I really appreciate all your help. Saved several hundred dollars thanks to you. Sniper