Merc 250 Verado Fuel increase

[muc]

 

[alldodge]

Guessing this is LED's on the throttle handles, and if so I have not watched for them during start sequence

The isolator (might also be a combiner) and and fuse I found


Wiring diagram


So looks like it's a combiner and haven't found anything to change House yet, but may be behind the Boat switch panel

 

[muc]

The Dual‑Engine Battery Architecture Diagram I posted comes from the
VERADO V8/SEAPRO V8 INSTALLATION MANUAL p/n 90-8M0156798
This should have been in your owners packet that came with the boat.

The Start/Stop All Engines I posted comes from the
Electronic Remote Control OPERATION MANUAL GEN 2 p/n 90-8M0180922
This also should have been in your owners packet.

It's possible that you didn't get them ---- I have worked with techs that felt it would "just confuse" boat owners, so They throw them away.
If you don't have them, I'm guessing you can call Merc for a free copy. They maybe even be available online under owners resources.

 

[alldodge]

I did find the install 8M0156798, it was in another folder

I can down load the Op manual, but mine starts port first, so the boat I'm thinking was wired wrong

Edit: found paper 8M0175493 Op and Maint

 

[alldodge]

Accomplished Gen 2 Control test SB 2025-05R2 and no beeps

Verified the pic in post 62 is a combiner

ALT test SB 2021-21
Unknown if I have isolator's or not, if they are installed they must be behind the Bat switch panel. Knees were getting to me so did measurements at motor, ALT and Bats

Key OFF Eng Off
House 12.5
SB Bat 12.67
PT Bat 12.73

Key On Eng Off
House 12.49
SB Bat 12.56
PT Bat 12.59

Key On Both Eng Run
House 14.29 to 14.30
SB Bat 14.4
PT Bat 14.5
Voltages at ALT or Motor connections the same. Thinking there isn't any isolator's because voltages at ALT are same as Bat

If I turn the keys ON and press start button before VV fully wakes up, I get beeps. Last season I could do the same and no beeps, also if I wait for VV to wake up there are no beeps. Difference between last season and this is the Bats measured slightly higher voltages 12.8

At the combiner the center post measured 13.9 to 14.1, the left post measured 13.2 to 13.5, the right post measured 13.5 to 13.8

 

[alldodge]

When starting motors using start/stop the throttle handle LEDs were lit before during and after start, run and shut down