2006 50HP Merc 4-stroke blowing 20 amp main relay/accessories fuse

[fundadore]

I have found similar questions in archives but no answers or troubleshooting steps.

Well, there you have it. Engine ran great for 5 years then leaves me floating down the river. It will blow that fuse nearly every time I try and start it. Boat (Tracker 170) is garage kept.

What parts does this fuse control?

I did catch the prop on the rocky bottom going very slow but it ran fine for 3 more hours. When the fuse blew, I had a very hard time shifting into reverse. but now I can shift easily. Prop spins freely in neutral in both directions, locks in reverse, locks in forward but I can make it turn backwards.

Appreciate it, gentlemen.

fred d.

 

[BillGowan]

Re: 2006 50HP Merc 4-stroke blowing 20 amp main relay/accessories fuse

I have a 2004 25 HP Tracker that was blowing that main fuse block. I found out that everytime I turned the steering wheel all the way left or right it blew. Also when I grab the linkage in the motor, I believe it's the shift linkage it would blow. I disconnected a wire on the fuse block, it's either purple or blue with a white stripe and the fuse blowing stopped. I have no clue what the wire does but everything seems to work.

This wire had a lug on it that another wire was also connected to. The second wire is back on. I just left the one loose and all seems fine, so far.

 

[fundadore]

Re: 2006 50HP Merc 4-stroke blowing 20 amp main relay/accessories fuse

Update:

I snared two of my engineering buddies (ME and IE) and we took the boat apart to reveal all the wiring. No evidence of any abrasions. We did find a few unused terminals where the metal extended beyond the plastic protective sleeves. We taped off about 4 of those. It started every time. We also tested ohms and voltage and nothing unusual was detected. I checked the ground wire for the trim that is on the transom (in the water) and it wasn't damaged or loose. We hypothesized about all the anecdotal stories that I read here and elsewhere and didn't arrive at any ah ha moments.

I guess I'll go fishing.