2004 Tige 24V with Mercruiser 350 MAG MPI

[GUY_RPM]

Have a 2004 24v and boat started dying/stalling at idle last time out; now there is no voltage (actually see about 3.3v on meter) getting to the 12v side of the switch where the 2 heavier gauge red wires come in to the ignition switch. When you turn the key the buzzer will softly buzz briefly, nothing like normal start up, but that is it, no gauges, radio, etc. Have two brand new Interstate batteries, both see 12.8v with engine off, and amps are seeing 12.8v, checked and double checked terminals to make sure no corrosion and tight. Hooking batteries to charger or jump box did not make a difference. I finally jumped a fusable link from the power/bus bar under the dash to the 12v side of the switch, turn the key and everything powers up and works as it should (haven't tried to crank engine yet) But wanted to see if anyone else had experienced the stalling issue and the sudden no voltage to ignition switch. Any feedback would be greatly appreciated. Thanks!

[GUY_RPM]

Here is a little more info about what is happening. This past Sunday while we were just sitting in the water idling waiting for people to show up at the dock the boat died twice, each time it died I was able to just start it right back up with no issues. After it died the second time we decided to take it for a ride to see if it would die while at speed. It did not die again and had no other issues the rest of the day. Last night went to install a amp and when we went to turn the power on there was nothing, not even enough power to turn on the stereo deck. The rest of the story is covered really good above.

[cobra7421]

Make sure the big red wire on back of alternator didn’t break off from vibration. Also make sure all connections on the back of it are still there and hooked up right.

[boatwakes]

It’s your 90amp fuse located on the starter. Item number 8 in the diagram. Make sure your batteries are disconnected (remove the negative wires, when you do the replacement.

https://www.perfprotech.com/fuse-***...product/114382

[GUY_RPM]

Ok we checked the starter fuse tonight and it shows that it is good, good signal on both sides of it. As you probably read above we have a bush fix where we are jumping power from one side of the buss bar under the dash that has power to the starter so it will start. Tonight after checking starter fuse we took the bush fix fuse out and the boat started and ran for 10 seconds then just died and no longer had power. Put fuse back in bush fix and it started and ran great. I am starting to lean towards a bad neutral switch. If the neutral switch does not see neutral it would prevent power from going to the ignition. Looks like there is a relay on the motor in line with the starter and/or neutral switch on the throttle, does this relay also control power to the ignition switch? What are your thoughts? It is deffinitely a electrical issue and we have checked almost every connections. We checked the alternator tonight and it is making good power and has good connections. Go guys and tell me if i am on the right track.

[GUY_RPM]

One side of the buss bar under the dash has power and the other side of it has basically no power.

[GUY_RPM]

I had a buddy point out that a bad neutral switch would not explain why it dies once running. It would explain why i have no power once the boat has stopped running and wont start but i am thinking i can rule that out since it would not kill the motor once running. Your thoughts?

[GUY_RPM]

Well I wanted to post a conclusion to this post. It ended up being the main wiring harness that goes to the motor. When we turned the boat on in the driveway it barely beeped and had no power, we slightly touched this plug and it lit the boat up. We pulled the plug apart and used some fine sand paper to clean a little corrosion out of the female part of the plug and on the male side of the plug the post have slits down the middle of them so we used a flat head screw driver to spread these posts. We put it all back together and everything functioned as it should. We took it out this last weekend with a full boat and had zero issues. I hope this information helps someone else who haves this same issue. Below is a picture of the plug and where you can find it on the motor.PLUG.JPG

[freeheel4life]

Nice work. Thanks for the follow up. Dang intermittent opens/high resistance issues are pesky. Glad you got it sorted. Little bit of dielectric grease goes a long way too.

I cant help but wonder though, what happened to your trans cooler??

[GUY_RPM]

Dude that picture is not actually my motor. That was actually a motor that was on a motor stand at my local repair shop. My local guy told me this could be my issue so I snapped a picture of it so it would help me find it on my motor.

[freeheel4life]

Dude that picture is not actually my motor. That was actually a motor that was on a motor stand at my local repair shop. My local guy told me this could be my issue so I snapped a picture of it so it would help me find it on my motor.

Makes much more sense. I hadn't even notice that it wasnt in a dark bilge. Just saw the trans cooler lines and hose pulled off and got me thinking. The mud is clear now. Thanks for the follow up.

[gumby]

WOW!!!! good find. I would have never guessed that one.I kept watching this thread. I had nothing to offer you for help. Thanks for the follow up. If it were me I would take that tech some beer/or cash. Keep him in good grace.