2001 Sport Nautique electrical issue

[bcd]

I'm trying to help fix my friend's 2001 Sport Nautique. He tried putting it in the water this last weekend and couldn't get it to start. He thought it was a dead battery, even though it worked when he got it our of storage. They charged the battery and it started, so they put it in the water, and it was dead again. I stopped over tonight to look at it. He had his battery checked after charging it again, and it passed the test. The starter has 12 V at it, and if you jump the relay it cranks, but the dash is dead. If you put the disconnect/power/bilge switch to bilge, the bilge runs. I started with pulling the kick plate out and measured voltage at the breaker box. There's a positive and negative post there. Maybe I was measuring wrong and not getting good contact (it was hard to get to even with the kick plate pulled out a little), but I was seeing 0 volts. Next I pulled the dash out and measured the power going to the port keypad side, and suddenly there was 12 V there. I plugged it back in and the boat started just fine. In between, we were messing around with a few different things, but not sure what we would have done. After the boat started, we messed around again, things like turning the disconnect to off, and the boat stopped working again. Now there is still 12 V to the port side keypad (horn, start switch, etc), but it doesn't work. I also see 12V at teh breaker box on the kick plate now. We also noticed that most of the lights are lit up on the starboard keypad side for things like shower, etc. If you turn the disconnect to off, they turn off, but turn back on when you turn the disconnect back to on. Pushing the buttons doesn't do anything.

I see there is power, ground, and 2 other wires going to each keypad. Are those on a CAN bus? Is there a controller somewhere running them? I've looked at the wiring diagrams on this site, but can't make much sense of what's going on since they are incomplete. The only controller I can find is the PCM one mounted to the engine. Any ideas what's going on here? The only idea I have is the controller is going bad, but don't know if that would be the PCM one on the engine, or if there's another one somewhere else I can't find.

You guys helped me with his positive battery cable corrosion issue a couple years ago, so hoping you can come to the rescue again.

[bturner]

I'm sure there's better people to comment on this than I but I'll comment on what I would look at.....

• First are you seeing 12 volts at the battery or are you using this as a general term meaning you're seeing at least 12 volts? I ask as a fully charged, healthy battery will see closer to 13+ volts. In my mind seeing 12 volts means an old and failing battery. If it were me I would find another battery (maybe from your boat) to swap into this boat and see what happens. This is a quick and easy test and will quickly eliminate the battery from the equation. You probably could have done this quicker than pulling the panel and lesson your changes of screwing something else up in the process which unfortunately happens frequently when troubleshooting (ask me how I know this).

• It sounds like you have a power switch of some sort and the issue can be somewhat reproduced by turning the switch on/off. These switches are notorious for going bad and I've had a couple literally fall apart on me. A bad terminal or contact will create a voltage drop or open circuit which kinda, sorta sounds like what you may have going on here. Depending on where the battery and switch are located you may be able to bypass the switch at the battery or you could move the the cable to the switch post going to panel and eliminate the switch from the equation. You could also take the more professional approach and take ohm readings across the switch to see if there is any resistance in the poles but what fun is that? PLEASE NOTE that the battery should be disconnected before doing any of this.

• Being an older boat bad connectors ,cable ends, corroded terminal posts or a failing switch are all places to look and should be considered low hanging fruit for diagnosis. Don't over look the condition of the ground on the block or the connection going to the starter. Any cables ends that look swollen would be suspect as this is typically an indication that you could have corrosion in the cable end going into the cable jacket.

• Lastly look for anything the owner may have added even if it was years ago. I see a lot of issues coming from old stereo upgrades where non marine rated cables and connectors were used. This is especially true of owner installed dual battery installations and power switches. Installations with non marine rated material may work well on day one but as they age will begin to fail with sometimes strange symptoms.

In case I didn't make it clear previously be very careful when playing with the power connections going to the battery. Those cables are large for a reason and can pose serious issues quickly if shorted or grounded. Hope this at least provides some places to look.

[jmo]

The keypads have been known to go bad, and when do the side effects are inconsistent. I accidently bent the square 4 pin connector on the back by pulling the dash pod off without releasing it first, and that caused the boat to sporadically shut off from interacting with the dash.