2019 Yamaha 200HP Blows Main/PTT 20amp fuse intermittently

[coldpizza]

I have two 2019 Yamaha 200HP (inline 4) motors on my 2004 GW Gulfstream. It has about 120 hours. During last year's season, it has developed an annoying issue to blow the Main/PTT 20amp fuse intermittently. When is blows, the engine shuts down and the guage on the dash does as well. It is the port (left-hand) motor. The mechanic thought they had 'fixed', found a loose connection on the engine. Took it out, same problem again. It is at the mechanic again, and they found different loose connections (these are bolt/connections not plugs) at the engine (send me a video where). The two he found loose (in video) was the one without a cap (red dot on it) and the one directly to the right. Not loose that you can see it, but but if he touched the cable it moved). They are going to review all 12V connections. I am wondering if there may be another problem, like a short that has chafed in the circuit between the engine and the dashboard. Only thinking that since the motor is relatively new, but the wiring from the engine to the dash are original (as far as I can tell). Any ideas where to start troubleshooing if the loose connection does clear the issue?
Thanks in advance.
Len

 

[seasick]

Usually a loose connection does not blow a fuse. Only an overload will normally do that.
Your though that it might be a bare wire somewhere is possible but so is a short in a dash control, like the ignition switch or other devices powered from the motor harness. That might include a dash engine stats screen.
Digital throttle and shift may also be a place to look. Sorry I can't be of more help but this problem may be difficult to track down.

 

[coldpizza]

Usually a loose connection does not blow a fuse. Only an overload will normally do that.
Your though that it might be a bare wire somewhere is possible but so is a short in a dash control, like the ignition switch or other devices powered from the motor harness. That might include a dash engine stats screen.
Digital throttle and shift may also be a place to look. Sorry I can't be of more help but this problem may be difficult to track down.

Thanks, I am skeptical of the loose connection as well. I thought more in the short or bare/chafed wire somewhere. I am trying to track down a wire diagrame (or a Service Manual) for my motor; difficult to find. Thanks for the response and I'll post what happens the next time I use it. I am picking it up from the mechanic, a certified Yamaha Tech tomorrow. Take care. Len

 

[coldpizza]

I'll be 'trying out the fix' that the mech said was needed. I've had another thought (that can be dangerous ), that maybe it truly is an issue in the trim/tilt (that is how the fuse is labeled; Main/PTT). If it blows, I plan to replace the fuse again, but run it without changing the trim and see if it stays stable. The run it changing the trim alot. I don't think that has had a correlation yet, but I am not finding any other issues until I figure out a better way to determine what is going on. These intermittent issues are are pain to troubleshoot.

 

[seasick]

wiring diagram for the engine would normally be in the service manual, Wiring for the harness, dash gauges ,batteries, key switch etc would be in the Yamaha rigging guide. O do not have one for 2019 or near to that motor year.

If you are saying that the trim angle of your motor changes as you run the boat, that is a problem with the tilt/trim system but in itself would not pop a fuse. If on the other hand, you have to constantly adjust the motor trim to maintain correct angle, that might over load the circuit especially if the motor is trim motor is stalling.
You should be able to tell if the trim motor is laboring by listening to it at the dock while you adjust the trim. You should check and top off and bleed the fluid before anything else .

 

[coldpizza]

wiring diagram for the engine would normally be in the service manual, Wiring for the harness, dash gauges ,batteries, key switch etc would be in the Yamaha rigging guide. O do not have one for 2019 or near to that motor year.

If you are saying that the trim angle of your motor changes as you run the boat, that is a problem with the tilt/trim system but in itself would not pop a fuse. If on the other hand, you have to constantly adjust the motor trim to maintain correct angle, that might over load the circuit especially if the motor is trim motor is stalling.
You should be able to tell if the trim motor is laboring by listening to it at the dock while you adjust the trim. You should check and top off and bleed the fluid before anything else .

Thanks for the response. I don't know if there is any issue with the PTT, I am just trying to narrow down what could be causing the 20amp fuse blow without a symptom that is readily able to determine the cause from. The tilt/trim seems to work without any issues. I think the idea of cycling it to see if that does it. I have noticed a few times that I have to trim the engines using the button on the binnacle independently.
I didn't find the wiring diagram in my owner's manual. I ordered on from Boats.net but seems it may be backordered. More to come after I get back to the boat. Thanks again and take care.

 

[seasick]

The diagram wont be in the owners manual, it would be in the Service manual. Some of the generic service manual like you would find at places like West Marine would probably have the engine wiring diagram.
As mentioned, harness and everything forward of the engine won't be in a service manual but rather in a rigging manual. You might find some wiring info for gauges and ignition switch online and it will be helpful to know the part numbers of your instruments.

 

[Sauza45]

You said that you have to use the trim buttons on the binnacle independently, there could be a short in the wiring in the binnacle. I would look really close at the wiring and see if there is any chaffing.

 

[seasick]

"Have to use the trim buttons on the control independently"
As opposed to what?
When the trim on the motor changes is it always in the same direction? If so, a trim button may be intermittently activating. If it got turned on in the up position, you would notice as the prop blows out but if it gets stuck in the down position, you may not notice at all but eventually I suspect the fuse would blow out due to overload.

The idea of an intermittent short is also interesting.
When the motor shuts down, do you remember if you were doing something like trimming or was it out of the blue?

 

[Chessie246G]

Usually a loose connection does not blow a fuse. Only an overload will normally do that.
Your though that it might be a bare wire somewhere is possible but so is a short in a dash control, like the ignition switch or other devices powered from the motor harness. That might include a dash engine stats screen.
Digital throttle and shift may also be a place to look. Sorry I can't be of more help but this problem may be difficult to track down.

Back in 2014 when my Tracker was new, it blew the main alternator fuse (20amp) on its first run. Loose bolt down connection. Imagine being towed in on the first trip out. UGH!! Checked every connection on the boat the day I got it back.

 

[coldpizza]

Back in 2014 when my Tracker was new, it blew the main alternator fuse (20amp) on its first run. Loose bolt down connection. Imagine being towed in on the first trip out. UGH!! Checked every connection on the boat the day I got it back.

Thanks for the reply. So maybe there could be something to the loose connection. I'm taking it out Friday to Catalina Island (hopefully) for the Summer. And I bought a pocketful of micro 20amp fuses in case it blows. They were hard to find last year, when looking for a Yamaha packaged unit. I ended up getting a sku from a boat dealer that cross referenced to a Honda civic . This year I got a pack of 5 Bussman fuses. Take care.
Len

 

[coldpizza]

Thanks for the reply. So maybe there could be something to the loose connection. I'm taking it out Friday to Catalina Island (hopefully) for the Summer. And I bought a pocketful of micro 20amp fuses in case it blows. They were hard to find last year, when looking for a Yamaha packaged unit. I ended up getting a sku from a boat dealer that cross referenced to a Honda civic . This year I got a pack of 5 Bussman fuses. Take care.
Len

Slight update. After failing to get the boat running properly again, I took it to a different shop (the one they sold the new engines to me in 2019). After troubeshooting for a while, the mechanic contacted Yamaha. Apparently they found a bad 'diode' in the engine harness. It took a while to get the part, but it was installed and got my boat back yesterday. I will run it Sunday with my fingers crossed. In addition to the warranty harness replacement, I installed new (almost 20 year old) rigging harness (from helm to binnicle) and a new binnicle. I wanted to start out with fresh wiring and especially new connectors.

 

[coldpizza]

Had a good trip from to Catalina Sunday. A little frustration at the launch ramp. Port motor started right up, that's the one that has the problems. Starboard wouldn't start, not even turn over. After cussing on it, and that didn't fix it, I took truck/boat to back end of launch area. Worked on it for almost 3 hours before I figured out one fo the two paraled batteries connections wasn't connected. My guess is that the mechanic had to take the battery set-up apart to get the new rigging harness and didn't but it back. Between that and me cleaning up all electrical connections, it was good to go. By then the wind/chop picked up so it was a good test. Had to adjust friction of throttles on the water, which worked out okay as well. Hope the intermittent issue has been finally solved.

 

[coldpizza]

Update. After putting 30 hours, the fuse has not blown. I am a bit superstitious and don't want to jinx anything , but so far so good!