Voltage spike

[middlegriff1]

Ive been trying to find the culprit of this voltage spike for awhile now. I just installed an new alternator, starter solenoid, cleaned the starter positive connection and ground connections. New breaker this coming week.

After starting the boat and letting it idle for a couple min the breaker pops. Due to how Supra wired the 454's the boat will stay running because the alternator charge wires and the dash wires are all on the same post of the breaker. Before the breaker pops, everything seems to be reading correct voltage all the way down to the starter 13.8-13.6. After the breaker pops the voltage spikes up to 15.5-16. I've reset the breaker with the boat running and it pulls the voltage back to where its supposed to be.

Anyone have any ideas?

[Moor]

possibly a bad breaker. Sounds like you already have the fix on the way.

[Wylietunes]

The voltage increase you are seeing is likely due to the alternator losing load and going near full-field. Reset the breaker and the alternator is linked back to the battery and other loads. 15-16 volts is not going to trip a breaker, but excessive current draw will, which is how a breaker or fuse primarily functions.

You may have a bad breaker that just tripping even though current draw is normal, or you could have excessive current draw and the breaker is doing its job.

[middlegriff1]

Thanks moor, and wylietunes. Ill post my findings when I install the new breaker

[CJD]

+1...High voltage with zero load is normal. Figure out what is causing the breaker to trip.

[Moor]

i had a similar issue on my old CC Barefoot Nautique. Same PCM 454. It ended up being the breaker.

[middlegriff1]

So half the problem fixed. New breaker solved the issue for the starting battery. So now, i can start and run the boat no problem with voltage spike or breaker tripping. But when i switch the perko over to battery 2 which has the sounds system on it, the breaker trips. The sound system is completely independent and only powers off battery 2. Own toggle switch for power to headunit/ interior speaker amp/ sub amp. And another toggle for the remote to the tower speaker amp. I've looked around for loose connections and nothing seems to be out of place. Any ideas?

[Wylietunes]

the breaker trips

Breaker just replaced or a different breaker?

[middlegriff1]

New 50a breaker. I had the boat out this weekend and left the perko switch on 1 with no breaker problems. Had the tunes on and just ran the 2nd battery down. After trying to charge the second battery the breaker pops.

[Wylietunes]

Something is not wire correctly, creating a short when the house battery is brought on line or charged. One obvious thing, is the fact that the audio is wired battery direct. Id address that while in there rewiring.