fuse to starter keeps blowing on 25hp 4 stroke

[1scoyote2]

I have a 2004 yamaha 25hp 4 stroke electric start (push button) and I let it sit for about a week then when I tried to start it, nothing....not even a click.
Batteries are just fine, both of them have over 12v and I have a battery switch so I can throw both batteries at the starter if needed.....but that is not the issue.
Pulled the shroud and there is one fuse, it's a 20A fuse and it was blown.
Put a new fuse in and it blew immediately.....did it again....blew it immediately again.

Took the electrical tape off of all the wires and chased them down....all in good shape....taped them back up.

I have 12v from the battery to the starter.....battery cables are good all the way to the motor.

Tested continuity from the push button to what I'm calling the solenoid and wires are in fine shape.

So....I shorted across the solenoid (like you used to be able to do with a car back in the day) and when I short across the solenoid it cranks and it will start and run.

That makes me think the solenoid is bad......but would a bad solenoid immediately blow that fuse?

I've never seen a solenoid act like that before.....but that doesn't mean it can't happen.

Anyone ever have this problem or any ideas?

Thanks in advance for any help......

[robert graham]

Are you sure you don't have your battery cables/terminals switched?....that will blow that fuse every time....I've done it several times myself...

[zenoahphobic]

Are you sure you don't have your battery cables/terminals switched?....that will blow that fuse every time....I've done it several times myself...

The Op says bridging the solenoid the starter works and engine starts, so that is not it.
I would think the solenoid is faulty whereby the wire in or coil has a short. It probably has had water in it at some time, causing current to travel where it shouldn’t, or corroded internal terminal maybe to a point where wire may have fallen off and then contacts the casing inside.

[1scoyote2]

I think the solenoid is bad also....but I'm mainly a shade tree auto mechanic ....and I've never seen a solenoid throw a fuse in a car/truck.

[99yam40]

is the fuse blowing without you trying to energizing the starter?
if so that should not be the problem because the solenoid should not have power to it until you hit the start

[boscoe99]

I am not seeing a solenoid used on the F25ESHC model. I suspect that you mean the starter relay.

Disconnect the power wire from the relay that runs to the starter motor. Then energize the relay by pushing the start button. Does the fuse blow? If so, that would indicate to me that the relay is faulty.

A double check would be to disconnect the brown wire to the relay. Push the starter button. Does the fuse blow? If so, that would indicate to me a control circuit wire problem. Not a relay problem.
zrelay.jpg

[1scoyote2]

To start with.....thanks for making an effort to help me....it's appreciated.

OK.the Year is 2004.......Model F25ELHC fuse.jpg

The fuse pops immediately .... before you push the starter button.....on contact it pops.

I removed the brown wire from the relay.....still pops the fuse

I disconnected the wire from the relay to the starter.....still pops fuse on contact

I'm running out of fuses!

This boat gets used a lot except it sat for a week and when I launched it I had this problem.

Was running when I put it away, pops fuses immediately the next time I took it out.

I removed all the factory electrical tape from the harness and chased every wire.....they look perfect, no bare spots that I can see.

I tested continuity from starter to relay, fuse to the starter button and red wire to regulator....all in good shape.

[99yam40]

well one of the wires it shorted to ground, just need to figure out which one.
disconnect wires and test to ground

[1scoyote2]

99yam40 - I have chased every wire in the harness....they all look just fine.

Whatever happened to it happened while it was just sitting in the carport.

The fuse is between the regulator and the relay......

the single red wire goes to the starter relay and on the other side of the fuse one red wire goes to the regulator and the other one goes to the starter button.

All of them check for continuity....none of them are grounded.....all are clean, no corrosion.

I can short across the starter relay and the motor will start and run, so, my question was if the starter relay could cause a direct short like that?

The starter button, the starter relay and the rectifier/regulator are all that are on that circuit as far as I can tell.

[99yam40]

disconnect them all and then hook up on at a time to see what blows the fuse.
RR can do it, but does not make since that the fuse will blow immediately without something going to ground

[TownsendsFJR1300]

Sounds like a dead short inside that relay.

As noted, disconnect wiring, hook up and see what blows the fuse.

That relay is $60 and do go bad (as noted, never heard of a dead short inside)..

Part #13: https://www.boats.net/catalog/yamaha...c/electrical-1


I'd personally cut that relay open (it's useless at that point) but should be obvious "damage"/issue inside.


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[1scoyote2]

TownsendsFJR1300 and 99yam40 - I gotta think relay too....but I was hoping I wasn't the first with this issue.

I'll disconnect from the relay and put my last fuse in there....then start hooking up and see when it blows....that is about all that is left.

[TownsendsFJR1300]

TownsendsFJR1300 and 99yam40 - I gotta think relay too....but I was hoping I wasn't the first with this issue.

I'll disconnect from the relay and put my last fuse in there....then start hooking up and see when it blows....that is about all that is left.

If you have a lighter fuse, you can burn those up first. With the dead short, it'll burn up immediately anyway.

My starter relay acted up years ago, just no crank 1/2 the time(no dead shorts). Installed the new one and cut up the old one just because.
Contact points were visibly burned up and was the issue:

F150 starter relay.JPG


Had a similar issue with the T&T relay, again opened it up and saw burned up contacts.

[1scoyote2]

Just to close this thread......it was the regulator/rectifier

Purrs like a Yamaha now

[TownsendsFJR1300]

Just to close this thread......it was the regulator/rectifier

Purrs like a Yamaha now

Was it shorted or ?

And thanks for the follow up!

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