2008 VLX, Electrical issues.

[Bwiggle]

I bought an 08 VLX with just over 400 hours about 4 months ago. The next day we splashed it and went for a ride in the cold.  After the first ride the plug was not taken out & here in southern Alabama it rained...a lot. 
When I got in the boat to get some gear out it was full of water. It was above the oil pan. so I took the plug out drain the water checked the dipstick & noticed some water.
(no water in cylinders) 

I turned the boat over, did not try to crank it, just to make sure I still had electrical connection. I took it straight to a marine repair to I have them fully drain all of the oil from the pan plug and do this 3 times to make sure all the water was out. When he cranked the boat up for the last time he couldn’t get it to shut off so he changed the key ignition switch. (Oil & key switch, $796)

I was told by the original owner that you always need to switch the batteries breaker to OFF, or it will drain them. I told the mechanic this.

So when we splashed the boat yesterday yesterday the batteries were dead. I jumped it off. We went cruising and boarding and I noticed that most gauges weren’t working and I was getting the occasional beeping with code “system fault“.  Most of the gauges started registering about two hours later, on our way back to the dock. When I unloaded everyone and sent my wife to splash the trailer, I couldn’t turn the boat off. I had to open the motor bay and pull the distributor wire ( nothing like a little jolt⚡️ of electricity to get you woken up and pissed off.)
 

I’ve got some electrical issues and wanted to know if anyone has had experience with these and can give me a good place to start. I am new to Malibu and inboard motors in general. But I do have a mechanical understanding so I’m going to try this myself.

THX IN ADVANCE!!

[csleaver]

Check all of your battery connections first, make sure all of the cables are tight and connected properly and there are no disconnected cables.  Also check your ground cable connection on the engine bell housing.

Splitting the potential problem between the engine wiring and the boat wiring will help narrow down an electrical issue.  By disconnecting the main rectangular 16 pin boat to engine harness plug near the ECM bracket you can isolate the engine wiring from the boat wiring.  To start and run the engine, back probe the engine side plug at the red wire pin A, the purple wire pin J, and yellow/red wire pin S.  Connect red A and purple J with a jumper wire to turn on the engine ignition power, then briefly connect yellow/red pin S to red A to crank and start the engine.  Remove the A to J jumper wire To stop the engine.  Check the engine ignition circuit for a short to power, possibly from the lead to the alternator, if the engine will not stop.

If the problem is in the boat side, you can isolate the main harness 16 pin connector under the helm from the dash harness in a very similar way to narrow down where the problem may be. 

To check for diagnostic trouble codes use your dash info center setup menu, select service, then fault codes to see any active or inactive SPN FMI code numbers.

Edited May 17, 2021 by csleaver

[Bwiggle]

@csleaver copy solid, thx.
I will start that break down tomorrow and update.

[Bwiggle]

Hey man so I’m in the middle of trying to get this squared away right now.

I don’t know where this ECM is to look for the 16 pin connector.

I started with obviously cleaning all battery cables and terminals correctly and turned it on again and it wouldn’t shut all so trying to go to the next step.

Is there a way to send pictures on this site? It’s highly annoying.