Ignition fuse (15A) blows intermittently

Jshear

Recruit
Joined
Aug 21, 2017
Messages
4
Hi,

I am new member to this forum and after reading some posts it seems like everyone is very helpful and knowledgeable. I really hope someone has some insight to this very frustrating issue. I did read some other threads but I don't see the same symptoms.

I have a 1999 Bayliner Capri with a Mercruiser 3.0 (S/N 0L333975)

2 weeks ago my ignition fuse (15A) kept blowing. Up until then the boat was running perfect. I thought I narrowed the issue down to my starter solenoid, as when I removed the sender cable the fuse did not blow. I replaced the entire started, but this weekend it happened again. The problem is that it does not happen all the time, it is very intermittent, but happens every time I am out for the day. Sometimes I turn the key and the fuse will immediately blow, other times the engine will be running and the fuse blows. Other time I will have the boat out for an hour, come back and then when I'm ready to go again the fuse continuously blows. I wait an hour or so and everything is fine for a little while. I traced the cables from the front to the back, I even took the side panel off to expose the cables, and everything seems ok. I was hoping someone had some insight as to what it could be, as well as if you can refer me to a place I can purchase a repair manual (I have the service Manual) so I know how the ignition wiring run and what components they are connected too. No other fuses blow, but all the gauges stop working when the 15A goes. In reading some articles some people reference a harness that runs under the engine that may be getting wet, not sure if I have that harness. To me it sounds like it could be a moisture issue, but where and why I don't know. My next plan is to replace all the terminals on the cables that attach to the battery, starter Solenoid and even the alternator as they are rusty, but don't expect that to fix the problem. This is a very frustrating issue that I really hope someone can provide some direction on. Thanks to everyone in advance for any information or suggestions you can provide.
 

Jshear

Recruit
Joined
Aug 21, 2017
Messages
4
Thanks for the response, Interesting, the fuse was always a 15A and its not in the line its a GMT fuse in a fuse box under the dash. This is the 2nd year owning the boat and have never had any issues except the last 2 week. I was doing some reading and there is a part on the starter solenoid that the red/blue cable comes off of and goes to the front. Its a little box (see picture) will this be called a slave Solenoid? I did not change that part could it be causing the problem?

so the pin bolts to the starter solenoid and is clamped to the main Red power cable coming from the battery. Then the Red/Blue bolts to the box and goes to the front.
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alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,539
Need to post some more times before you can upload pics. My guess is the fuse blew once before and was replaced after fixing the problem and only had a 15 amp. Below is the basic wiring in the engine compartment

3_0L wiring Diag.jpg
 

Jshear

Recruit
Joined
Aug 21, 2017
Messages
4
Thanks I am going up this week, ill put a 20Amp in and hopefully that will do it. Appreciate the help!!
 
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