I'm experiencing a problem that's tremendously similar to that of scott76310's in his older thread, very tough circuit breaker question on Volvo 5.7GS.
I have a 1994 Cobalt 255 that has a fuel-injected 5.7GI Volvo Penta.
The exhaust riser carries three breakers. Occasionally, the 60 amp breaker will pop when we turn off the engine. This has been happening more frequently lately, but certainly doesn't happen every time we stop the engine.
Unfortunately, I struggle against a barely competent shop. Until I find better help, I'll need to at least make an attempt at diagnosing the problem myself.
The alternator was new last season. The shop that replaced it completely botched the job, leaving me with a bad over-voltage situation: that's the first time that the 60 amp breaker ever popped. It took with it my tachometer and trim gague.
They replaced the alternator and the boat ran fine for the balance of last season. I replaced the tachometer and it works. I replaced the trim gauge and it is still inoperative; the shop said the sender is fine, but I haven't tested it. The boat also has a "black box" between the sender, the trim control, and the gauge. I have that part, but haven't replaced it yet.
With the new alternator, we noticed better charging than ever before: the voltmeter on the helm indicates 13.5 to 14.0 volts whenever it should be charging. But this season, the 60 amp breaker started popping at key-off. The tachometer has also failed again.
In scott76310's thread, he says that he believes he fixed the problem by moving the sense wire on the alternator, but it's not completely clear to me what he did. He also doesn't report back to confirm that the problem was completely solved for him.
What's a likely cause of this problem? How can I best diagnose it?
I have a 1994 Cobalt 255 that has a fuel-injected 5.7GI Volvo Penta.
The exhaust riser carries three breakers. Occasionally, the 60 amp breaker will pop when we turn off the engine. This has been happening more frequently lately, but certainly doesn't happen every time we stop the engine.
Unfortunately, I struggle against a barely competent shop. Until I find better help, I'll need to at least make an attempt at diagnosing the problem myself.
The alternator was new last season. The shop that replaced it completely botched the job, leaving me with a bad over-voltage situation: that's the first time that the 60 amp breaker ever popped. It took with it my tachometer and trim gague.
They replaced the alternator and the boat ran fine for the balance of last season. I replaced the tachometer and it works. I replaced the trim gauge and it is still inoperative; the shop said the sender is fine, but I haven't tested it. The boat also has a "black box" between the sender, the trim control, and the gauge. I have that part, but haven't replaced it yet.
With the new alternator, we noticed better charging than ever before: the voltmeter on the helm indicates 13.5 to 14.0 volts whenever it should be charging. But this season, the 60 amp breaker started popping at key-off. The tachometer has also failed again.
In scott76310's thread, he says that he believes he fixed the problem by moving the sense wire on the alternator, but it's not completely clear to me what he did. He also doesn't report back to confirm that the problem was completely solved for him.
What's a likely cause of this problem? How can I best diagnose it?
Last edited by a moderator:
