Main Breaker Trips

[saltare inverts]

When I run my boat it runs perfect. Every time I shut off the motor the main breaker by the motor trips. I reset it then shell run fine again. This happend about seven times before I stopped running the boat because I couldnt figure out the problem. This all happened on the water, didnt matter if I hade stereo on or off. Any suggestions or answer on how to fix this dilemma would be great. Of course, right before memorial.

[Supra-in-steamboat]

Go figure just before the weekend... Did you notice the volts you were producing while running? I think normal charging is @ 13.5-14.5 . If they are high, maybe the alternator is sending to much juice around. I am not sure that would directly cause the tripping. The breaker itself could possibly be going bad- again possibly- but more likely the case is recieving more juice than it wants. Maybe start with the basics- check that you have tight, clean connections at battery/batteries, ground, etc.- and that your not producing to much electricity. Hopefully this won't lead to searching for a short/fault of somekind. Good luck and hope this helps.

[saltare inverts]

Well I just put in a second optima battery with all cleaned or new connections on both batteries.. The breakers is also brand new. The alternator is a new DB last year rated at 140 amps( i think). It ran fine with new alt last year. I also replaced all connectors to the back of the starter switch. The breaker is new because it tripped and locked open. So I am getting a surge of juice(I guess) somehow. Help!

[saltare inverts]

SO I just did a bench test on my boat in the yard. It will only trip the breaker at 3/4 of full speed on throttle when its there for over 10 seconds. It doesnt matter if any accesories are are or not. I tried it several ways. So Im guessing it has something to do with ignition? I am still lost.

[OUI]

Try disconnecting the alternator to see if it still trips the breaker at 3/4 throttle.

[sybrmike]

I hope it's not the alternator. My 140 amp DB just showed up yesterday. Keep us posted & good luck!

[saltare inverts]

It was a loose connection on the back of the keyed starter switch. It was loose and the wire was a little black at the end. I replaced the wire and ends, reattached and problem seems solved. Of course I will check it on the water tommorow. Cant wait to see. Thanks for ideas.

[saltare inverts]

Thought I had problem fixed until I took her out Sat. With further investigation I noticed the trans getting real hot. I assuming it is getting hot because trans cooler is bad or clogged then the heat trips breaker witch is above the trans. What I cant figure out is why my volts are running at 15.5 when at high rpms. Any ideas thoughts or answers?

[tad2lo]

Would it be necessary to up the size of your circuit breaker to compensate for the higher output alt you have???

[michael hunter]

It sounds like you have two problems. Trans temp and voltage.
Are you checking the voltage with the dash gauge or a volt meter? 15.5 is very high it should never go above 14.5. You will start damaging electrical devices if it continues. Sounds like the voltage regulator is bad. Its probubly inside the alt. Check the trans fluid and cooler for clogging ? I dont know that much about the trans maybe AL can help ?