Keep blowing 20amp fuse on 150 VMax

[Strid56]

Have a 2000 150 VMax on my Maverick MA 18.5. All of a sudden I've started blowing the 20 amp fuse on port side of engine. I can't tell when it happens but it's located next to the 30 amp fuse and they both run next to the trim switch. I replace the fuse and able to work the power trim up and down continuously, run the motor, and shut it down for the night, but when I do the same several days later, it's dead and fuse is blown. The only 3 three steps I do are, turn the battery switch on, run the engine, and run the trim up/down, shut the motor off, and turn battery switch to off. I don't know where to start on looking for a short, all connections appear to be solid. Any ideas would surely help in my brainstorming.

[flatwater]

Same thing happened to me once. Check the ground on your tilt/trim.

 

[SCFD rtrd.]

On some outboard motors, the wires from the trim motor to the relays is not one continuous wire. They are two separate wires and the connection is lying in the bottom of the pan, which makes them subject to corrosion. You might want to trace the trim wires from the trim motor, up through the pan and up toward the relays.

[Wanaflatsfish]

13 hours ago, Strid56 said:

Have a 2000 150 VMax on my Maverick MA 18.5. All of a sudden I've started blowing the 20 amp fuse on port side of engine. I can't tell when it happens but it's located next to the 30 amp fuse and they both run next to the trim switch. I replace the fuse and able to work the power trim up and down continuously, run the motor, and shut it down for the night, but when I do the same several days later, it's dead and fuse is blown. The only 3 three steps I do are, turn the battery switch on, run the engine, and run the trim up/down, shut the motor off, and turn battery switch to off. I don't know where to start on looking for a short, all connections appear to be solid. Any ideas would surely help in my brainstorming.

17 year old wiring could have shorted somewhere along the way...

AS mentioned, check how the connectors are made and be sure nothing has come loose inside the trim unit on the throttle...

 

Shorts etc. are NOT easy to diagnosis and usually require a Yamaha tech with the right tools..if it's not a quick fix, I'd bring it to a 5 start mechanic and have it fixed properly.

 

dc

 

[polliwog]

Blown fuse usually indicates a short somewhere.  If you are a good sleuth go at it .  I know where my strengths are and it's not electronics,so I would go to a pro.