Warning light coming on at idle; goes off when revved. 2008 SANTE 220 343 EXC

[billywro]

Engine temp, oil pressure, voltage in normal ranges, and boat running like usual. The red warning light comes on (solid, not flashing) at idle speed in neutral, but goes out when you give it some gas. Batteries are starting 6 season, and have enough juice to start the boat, but they are my primary suspicion. I don’t have a code reader handy. Any thoughts? Thx

[shag]

I have had a few Nautiques in the past and this seems to be a normal thing. I believe there maybe a safety plate that says something about seeking maintenance if it stays on above idle.... I want to say there is a 2psi electrical solenoid by the tranny that might turn that light on.

[bturner]

First thing I always try to go with is the stupid stuff. Fluid levels and condition are always my low hanging fruit.

[Scooter G]

Just my 2 cents following the good advice shag & bturner, our '03 Supra would do that from day 2 (2nd owner). Light would run constant at idle and off as soon as you bumped the throttle (at least I new it worked). Sold it out the door with 1300 hours, still running at the top of it's game. This sounds like a new issue to you, yes, any chance you just haven't noticed it before?

[billywro]

Thanks for the comments. I confirmed good levels on the transmission fluid, engine oil, v-drive level and coolant levels. The warning light coming on and off is definitely a new thing; nothing similar since I bought boat in late 2017. Glad to hear from Scooter G that it can be an ongoing, but benign, condition. Will put new batteries in this weekend and do a throttle body cleaning; hope. Thx

[hal2814]

Do you know which v-drive you have? Sounds like the light for a Walters unit. They had a red pressure warning light. As idle there was no pressure in the v-drive so it would be on. As you increase speed, it increases pressure inside the unit and the light goes off. If that’s the light you’re looking at it’s no big deal. On those if the light stays on while underway that means there is some sort of leak in the system.

[billywro]

It's the red light at the top center of the dash. My V-drive is the PCM Power Plus 1.48. Transmission is PCM 1.23:1. It illuminates when you power up the ignition, then goes out after the boat starts. Then it will intermittently come back on at idle speed in neutral, but go out when I give it a little gas. I ran the boat for 30+ minutes and never saw the light when underway.

[shag]

Do you know which v-drive you have? Sounds like the light for a Walters unit. They had a red pressure warning light. As idle there was no pressure in the v-drive so it would be on. As you increase speed, it increases pressure inside the unit and the light goes off. If that’s the light you’re looking at it’s no big deal. On those if the light stays on while underway that means there is some sort of leak in the system.

I think you're right... That is where the little 2 psi switch is... It could just be that switch... I want to say in a previous boat that I replaced that switch and the light rarely came on after that...

[H2O]

Check the specific owner's manual for your boat/engine. I believe that light is only supposed to light up under two conditions: engine overheat or low oil pressure for the Excalibur.

[bturner]

Could easily be a bad sensor as Shag posted. As H2O states knowing what trips the light would give you an idea where to focus and what to search on.

[billywro]

Thanks all for the great feedback; a bad sensor is now my leading suspect. I will try to isolate the issue by systematically plugging/unplugging the oil pressure and engine temp sensors. I will check to see if there's a sensor on the v-drive or tranny, but from what I've read, that may be only available on the Walters unit (I have PCM). Good news is I can replace the oil & temp sensors for less than $100, which won't kill me to do given the engine has 15 years in service.

[Spud]

Keep us updated on how you go with the fix... i would be interested to understand what it maybe!

[tomsyckn]

My old Supersport with the GT-40 did this too. Light would flicker when running but not in gear, go away immediately as the boat had any load put on it.... never found a solution and/or more importantly an issue that triggered it.

We did have one occurrence of overheating slightly when sitting but would cool immediately once underway and it was due to vapor lock from the strainer. When at idle the impeller was pulling small amounts of air in through the strainer seal but when underway water was forced through the system causing it to cool back down. This was also reflected on the engine temp gauge though, not just the light.

[jkallen21]

I believe the list of what makes that light come on is pretty limited - I know temp and oil will do it. Maybe others know the rest. You can order a codemate cheap to read the codes if it's storing any.

[billywro]

jkallen21 - Thanks! Can you recommend a specific codemate reader for a 2008 Excalibur 343?

Overall status update: ran boat about 2 hours this weekend, with all gauge reading for temp, oil pressure and voltage in normal range. The light only came on briefly a few times when at idle, much less frequently than before. Ordered new temp and oil sensors and hope to install this coming weekend.