2000 F100 4 stroke electrical problem

I just bought the boat yesterday. Of course never had a problem with it until now per the prior owner and I believe him. I went to start the motor at the ramp and put it down with the trim. Turned the key on, spun over about 5 seconds and quit. Nothing. No tilt, nothing.
Checked the battery for good connection. Eliminated the battery cut out. Nothing. Pulled the cover and found the top fuse, 20 amp, blown. Replaced with spare. Tilt and trim worked from motor. Went back up in the boat and everything appeared to be OK. Turned the key and POP. 20 amp fuse blown again. Checked the fuses in the console. 20 amp main there also popped. Just my luck.
Went out tonight and only hooked up the wiring to the console. All lighting and accessories worked with fuse replaced in console. Replaced fuse in motor. Tilt and trim worked. Turned key on and Pop. Console fuse and motor fuse blown again. Did a little head scratching before the rain ran me off and I think something is shorted somewhere back at the motor. I have seen the 30 amp fuse blow at the motor when the rectifier is bad. Never seen the 20 amp fuse blow when the key is turned on. Any ideas where to start. Boat has 150 hours on motor. Clean as a whistle. Previous owner out in it Friday. Ran fine.

Re: 2000 F100 4 stroke electrical problem

Yamaha motor. Sorry I forgot to put in post.

Re: 2000 F100 4 stroke electrical problem

No help?

Re: 2000 F100 4 stroke electrical problem

wblewzman said:

No help?

Click to expand...

You will have to troubleshoot with a meter to see what and where it is shorted

Re: 2000 F100 4 stroke electrical problem

I figured it out. Finally quit raining after 5 days straight. I found the lanyard kill switch was either wired wrong from the beginning or something has changed since I pulled it home. If the lanyard is not connected properly to the switch there is a direct short to ground. I am sure that is not how it is supposed to be wired. There is a wire that comes off the hot side of the ignition switch and goes directly through the kill switch. As long as the kill switch has the lanyard connected there is no problem. As soon as the clip is removed from the switch with the ignition on it blows the fuses.
I assume the kill switch should work off of a ground. Not a hot wire. I will have to do some more checking on Monday. I am sure the previous owner had never turned the ignition on with the lanyard clip disconnected. I got into the habit of removing mine every time I get out of the helm seat. I have kids and I figured that would be a sure way to keep them from turning the key and starting the boat when we are stopped and out swimming or something.
When I originally tried to start the boat for the first time, in my excitement I forgot to install the lanyard clip. The motor spun over but did not start. I realized the lanyard was not connected and I released the key to the ACC position and that is when the fuses blew.
Live and learn.
I will find out how to properly wire it up and get if wired up next week.

Re: 2000 F100 4 stroke electrical problem

what color wires are you talking about?

Red is the 12v + going to Key switch

Should not have 12v + from key switch going to kill switch, maybe harness has a short in it
as you said it grounds out the ignition system when lanyard is pulled off

Re: 2000 F100 4 stroke electrical problem

That was the problem. Incorrectly wired from day one. Previous owner never turned on the ignition switch (He never removed the lanyard clip) to the accessorie position with out the clip being installed in the kill switch. So he never experienced the problem. The Lanyard kill switch was wired directly to the accessory lug on the ignition switch. It would have worked. But once it died it would have not started back up until all the blown fuses were replaced. I am real surprised it did not take out the CDI by running 12V into the kill wire. I am going to properly wire the switch as soon as it quits raining here.