5.0 Mercruiser EFI - something causing push button circuit breaker trip on main panel

[trey3424]

New to iBoats but am desperate for help. 2000 Ebbtide 198 with 5.0 Mercruiser EFI. Boat will be running great, gauges reading normal. Randomly the oil temp/oil pressure alarm sounds simultaneously with the gauges starting to dance. The engine sputters and it shuts off. The push button circuit breaker trips, causing me to lose power to all gauges and the switch. I give the push button a few minutes until I can reset it. I usually have to give some throttle for it to fire back up. Sometimes I have 20 minutes until it does it again, sometimes I have 20 seconds. I don't think it is related to the oil temp or pressure, as the gauges will be reading fine before and after the episode. I recently replaced the alternator but I don't see how it could be related. I confirmed it is wired correctly. Any help troubleshooting would be greatly appreciated.

 

[ESGWheel]

Wow! Not fun. Suggest that this is a ground issue as in there is a loose / bad ground that intermittently shows itself and results in funky gauge readings, engine dies and breaker trips. The age certainly suggests it. Aslo which Bkr?

Check battery and all major connections, like the thick ground wire to the block, the pos wire to the starter etc. Do not assume simply by looking they are OK, pull them apart and get them bright / shinney. And even the cable terminal end can be corroded under the terminal and not apparent > ie the cable is bad but does not have the appearance of being bad. Peel back a little of the insulation at the end and if the wire is black > bad cable.

 

[trey3424]

Wow! Not fun. Suggest that this is a ground issue as in there is a loose / bad ground that intermittently shows itself and results in funky gauge readings, engine dies and breaker trips. The age certainly suggests it. Aslo which Bkr?

Check battery and all major connections, like the thick ground wire to the block, the pos wire to the starter etc. Do not assume simply by looking they are OK, pull them apart and get them bright / shinney. And even the cable terminal end can be corroded under the terminal and not apparent > ie the cable is bad but does not have the appearance of being bad. Peel back a little of the insulation at the end and if the wire is black > bad cable.

Appreciate the tips. I'll definitely look into these connections. Thank you

 

[Chris1956]

I think you need to look for a wire downstream of the circuit breaker, that carries power. It would be a thick wire say 8 gauge, and it would need to rub against the metal of the engine and have a bare spot where the insulation has rubbed off. You might see a burn mark as well.