fuse sizes?

[lkr]

This weekend after trying to start my 97 bayliner w 4.3 it just quit. It would not turn the starter but all other circuits worked. I found a melted fuse on the fuse block that goes to the keyed ignition switch. It was a 15 amp fuse and was burned and melted. I installed a spare that was 10 amps and everything worked fine. My question is the 15 amp large enough or should a 30 amp go there? Autos and motorcycles use 30 amp fuses on the starter circuit shouldnt a boat?

 

[Don S]

Re: fuse sizes?

The fuse is there to protect the wiring. If you have the standard 14 gauge wiring, then 15 is the max.
What you need to do is find out what the problem is/was, not just install a bigger fuse.
The only thing the fuse for the start circuit operates is a slave solenoid. Way less than 1 amp.

 

[lkr]

Re: fuse sizes?

I had been having a charging problem. The gauge was showing that there was only 10 volts at idle and it went down with increased rpms. I had the alternator checked thinking that was the problem but it was fine. I had just reinstalled the alternator and tried starting the boat. It turned over fine about 4 times and then quit. The fuse really wasnt blown it was melted to where it wouldnt make contact. When I put a new fuse in everything worked including the gauge showing right at 14 volts. So could a resistance wire for the charging system be going bad or could repeated hard starting cause this problem?

 

[thrasher]

Re: fuse sizes?

It could have been a bad connection with the fuse, that would cause a high resistance which would heatup when a high current was passed. I would suspect that this is a problem that has been happening over a long period of time and finally failed (based on your description of the holder being melted). As Don says, I would clean the fuse contacts and replace the fuse with the correctly rated fuse and keep an eye on the system for a while. If the problem was due to a bad connection at the fuse then cleaning the contacts will have solved the problem, if it's something else, then you will shortly see the new fuse blow.. Then the real work begins..

Gary

 

[Don S]

Re: fuse sizes?

It would not turn the starter but all other circuits worked.

When you say all other circuits worked, did that include the engine gauges? Did you have power to the ignition?
What color of wires go to the fues that melted and burned?
Other things like pumps, blowers, lights, etc are on a completely different circuit than the engine, or at least it should be.

 

[lkr]

Re: fuse sizes?

When I stated everything else worked I was speaking of the lights, radio, blower etc. No the guages would not come on with the bad fuse. The fuse block has a red wire w blue stripe that comes off of the circuit in question and goes to the ignition switch. I hope that it was a bad connection over a long period of time that caused this. I have had this boat 4 summers and the gauge has showed lower charging every year. The boat hasnt given me any problems until this so I will see how it goes. Thanks.

 

[Don S]

Re: fuse sizes?

It's actually a red/purple wire and is the battery connection to the ignition switch. It's supposed to be a 20 amp fuse.
What type fuse holder do you have, one with the newer ATC (automotive style) fuses, or the older AGC, glass tube type?


ATC

AGC

 

[lkr]

Re: fuse sizes?

The fuse is the newer automotive style. So you say that it is supposed to be a 20 amp? That would explain the 15 amp melting.