2019 115 Pro XS 4 Stroke High Voltage Spike

[fishhawk1750]

2019 115 Pro XS 4 Stroke
Serial #2B566136
Model #8117F131D

I am getting a High Voltage Warning - Long Steady alarm but only when I first take off and get up to full speed. I then put the boat back into neutral and the alarm stops. I am able to go the rest of the day without the alarm going off again, even at full speed.

I have the VesselView App on my phone connected to the VesselView module on the motor. It is telling me that this warning is for High Voltage:
621-24
System Voltage
The input circuit for the sensor is above the valid limit.

I bought this motor in March of 2019 - it is a remanufactured motor (so only 1 year of warranty). This did not happen until this year. I did not experience this last year.

I put on a new Voltage Regulator (Part #8M0088351). The first time I went out after putting that on I did not get the warning. It came back the next time out.

While in Canada last year, I had to get a new battery. The boat went in to get the transom rebuilt after that and was gone most of the boating season. I didn't have this issue in Canada or when I got the boat back last year. Picture of battery below.

Any help would be greatly appreciated.

Battery 1.jpg

[EuropeanAM]

Is this battery sealed, or a traditional wet-cell battery?

Was the replacement regulator an OEM Mercury Part?

Any browned, blackened or damaged connectors?

I would be looking carefully at the battery, it's connections (wrench-tight NUTS, do NOT use wing nuts), engine cables installed FIRST, remaining lugs largest to smallest.

LOAD test the battery (get a physical value in CCA that the battery "passed" the test with).

If possible, utilize a clamp-style post and connect to the LUG of that clamp style post.

Inspect/clean/properly tighten the ENGINE end of the battery cables also. Check for any signs of corrosion or deterioration in those cables.

Those basics should get you started...

[EuropeanAM]

fishhawk1750, I got the same error yesterday "Critical - High Voltage' on my 2018 Mercury 115 Pro XS. It alarmed at around 6000 RPMs but I could idle back to the dock OK. It started fine and idled fine when loading it on the trailer. I called several dealers but it will be a couple weeks before they can look at it; mine is still under warranty. I'm going to go out today to see if it happens again. I double checked all my battery cables and they look clean and tight and I didn't see any burnt wiring. I haven't had my battery load tested yet (regular lead acid) but it functions fine (charges fine, starts the boat fine, runs the sonar for a long time between engine runs, runs the nav lights at night).

Can you tell me how you fixed yours?

Thanks,
Bryan

Bryan:

Welcome to BBC!

If you would, please take a few moments to look through the Announcements at the top of the Forum, and open your own (separate) thread for your engine. Be sure to provide the Required Info (serial number).

Based on the information you have provided, I would strongly encourage you to get your engine in to an Authorized Mercury Dealer ASAP (preferably BEFORE running the engine again). High Voltage conditions can damage sensitive electronic equipment on your engine.

In addition to the battery and cables, the dealer will inspect the stator, stator wiring and the Voltage Regulator for problems. You likely DO have a failure in one of these components.