Circuit breaker broken?

[Sandpiper889xl]

I just replaced my 55 amp alternator with an identically spec’d one one my 83 SeaSprite (3.0 Mercruiser) and something weird is happening... It’s not charging my battery (12.3 v while off as well as while running). I checked all the connections and wires and have noticed nothing wrong or missing or broken, but this one oddity occurs: when I hit the red 50 amp circuit Breaker button while running and getting 12.3 v (at the battery and back of alternator), the rpms suddenly drop like it wants to bog down and stall, but then my multimeter reads 13.5-14 volts ( like it should be) for about 20-30 seconds, then the circuit breaker seems to trip or something again and my rpms shoot back up and the voltage drops back down to 12.3 v or so again.

I can’t find anything shorting or grounding, and everything is hooked up properly as far as I can tell.

Is my circuit breaker going bad? Should I put a 60 amp one in instead of 50 in case the new alternator is more efficient than the old one (even though is a direct replacement from DB Electrical)?

Any ideas or help is greatly appreciated.

 

[achris]

If you have a high load, or the battery is well down, then the 55A alternator will output, surprise surprise, 55A, and pop the 50A breaker. And at idle, the engine is certainly going to load up as the alternator tries to produce power.

Try charging the battery for a few day, then see if it does it again. If it works fine, then fit a bigger breaker.

 

[Sandpiper889xl]

I will try that, however, when it is idling after I just start it , for example, is when the multimeter reads 12.3 on the battery and back of alt. I also forgot to mention, the voltmeter in the gauge cluster is also pegged all the way to the right at idle.

while like this, I hit the red circuit breaker button and it clicks and instantly the rpms come down and engine nearly dies, my digital multimeter reads 14 v and the volt meter on the gauge cluster matches that at 14v.


it doesn’t make sense to me why this is occurring.

 

[alldodge]

Disconnect the bat and charge it. Check voltage while charging and if it doesn't charge at 14V then the battery has a short

 

[Sandpiper889xl]

Took off battery and charged it. Charged at 14. Took off charger over night and checked battery in morning and it was at 12.6.

 

[Bt Doctur]

considering the alt is wired direct to the starters battery post ,the 50A is not in the circuit

 

[Bt Doctur]

remove the output wire from the alt, reset the breaker , see if it pops. If yes, your wiring is suspect not the alt