Mercruiser 6.2 - 90amp fuse

[krisMa]

Hello everyone I need some help to understand the point of 90 amp fuse on mercruiser 6.2 inboard engine next to the starter.
Had a problem to start portside motor, long story short new fuse,new starter same problem.
So new mechanic came and removed fuse completely and motor start instantly, and work fine.

So questions is it dangerous to use motor without 90 amp fuse and if I need to put it back what can be a problem to engine not to start with fuse
thank you.

 

[04fxdwgi25]

Fuse is there to protect the wiring in the event of a short.

 

[tpenfield]

Welcome to iBoats . . .

Post the serial number of your engine to help with responses, but as stated the fuse should be there.

Not sure why a mechanic would remove the fuse. Also not sure why a mechanic would replace the starter. Maybe you need to consult a third mechanic.

 

[dubs283]

Main purpose of the 90 amp fuse is to protect the alternator and battery from damage in case someone connects the battery cables backwards. It's cheaper to replace the fuse than an alternator/battery

The 50 amp breaker protects the rest of the engine circuits from damage and has been present on mercruiser engines for quite some time

 

[Scott Danforth]

It wasn't the 90 amp fuse causing your issues. Most likely dirty connections

 

[krisMa]

Welcome to iBoats . . .

Post the serial number of your engine to help with responses, but as stated the fuse should be there.

Not sure why a mechanic would remove the fuse. Also not sure why a mechanic would replace the starter. Maybe you need to consult a third mechanic.

Thank you for welcoming me .
Engine MIE MX 6.2 MPI HORIZON
Serial number 0M310117.
The thing is motor was working with fuse and everything like normal and one day it's just stopped,not starting no life sounds, and then as I said mechanic came look up everything removed fuse and motor started working no problem, but I'm pretty new to boat and especially to motors and I start reading that it is not good idea to remove that fuse.
Thank you for your reply.

 

[krisMa]

Main purpose of the 90 amp fuse is to protect the alternator and battery from damage in case someone connects the battery cables backwards. It's cheaper to replace the fuse than an alternator/battery

The 50 amp breaker protects the rest of the engine circuits from damage and has been present on mercruiser engines for quite some time

Understood, I will put back fuse and see what will happen, if motor not starting I'll check alternator and cables. Hopefully it will work

 

[dubs283]

Understood, I will put back fuse and see what will happen, if motor not starting I'll check alternator and cables.

Test the fuse for continuity, if no continuity or very high and the contacts look questionable, replace the fuse

 

[04fxdwgi25]

It is working now. If you install the fuse (and it doesn't blow) and then it doesn't work, it is probably a connection / wire itself problem.

Check the fuse he removed and see if it is blown. No way a good fuse stops current flow, unless the connection is chit.