DF140ATL mystery electrical issues

[doug@5rivers]

My wife and I ran our Excel Bay Pro 203 with 2016 DF140ATL several hours today. I noticed as we were coming back to the dock, my tach wasn't working. It had been all day. I was afraid to shut the engine off until I docked the boat. Once I docked, the engine was shut off, key turned, and all 4 red system lights on the tach came on as usual. The engine started fine.The hand on the tach never moved. Still not working. I left it running for a few minutes while I backed the truck down the ramp. Once the boat was loaded on the trailer and taken up the ramp, I smelled smoke then noticed the insulation was melting off one of the ground wires attached to the lower unit of the engine. I quickly took the positive battery wires off the post.

I use 5 batteries on this boat, 3 golf carts for the trolling motor, one for electronics and one for engine and accessories.

I contacted my dealer and started looking for obvious issues. I checked under my dash, inside the bilge and found no burned wires or smell. The dealer had me unhook the power and sender wire from the tach then the square plug. I still have smoking wire at the engine ground. I've looked everywhere. I pulled the battery to have it checked in AM. I don't want to risk burning the wiring completely up even though the boat is under warranty.

Any ideas? It's like I have a dead short somewhere I can't find. No accessory switches were left on.

[Hoosmatroos]

If the boat is under warranty, why not let the dealer sort it out for you?

[redlowrey]

My wife and I ran our Excel Bay Pro 203 with 2016 DF140ATL several hours today. I noticed as we were coming back to the dock, my tach wasn't working. It had been all day. I was afraid to shut the engine off until I docked the boat. Once I docked, the engine was shut off, key turned, and all 4 red system lights on the tach came on as usual. The engine started fine.The hand on the tach never moved. Still not working. I left it running for a few minutes while I backed the truck down the ramp. Once the boat was loaded on the trailer and taken up the ramp, I smelled smoke then noticed the insulation was melting off one of the ground wires attached to the lower unit of the engine. I quickly took the positive battery wires off the post.

I use 5 batteries on this boat, 3 golf carts for the trolling motor, one for electronics and one for engine and accessories.

I contacted my dealer and started looking for obvious issues. I checked under my dash, inside the bilge and found no burned wires or smell. The dealer had me unhook the power and sender wire from the tach then the square plug. I still have smoking wire at the engine ground. I've looked everywhere. I pulled the battery to have it checked in AM. I don't want to risk burning the wiring completely up even though the boat is under warranty.

Any ideas? It's like I have a dead short somewhere I can't find. No accessory switches were left on.

''''''''''' It sounds like your talking about the bonding wire on the engine it is not a ground, but if the main negative battery cable which is bolted to the block near the starter is loose, all the current trying to get back to the battery negative post will take a path with the least amount of resistance.

Your ecu grounds are bolted to the block as well, including the rectifier ground wire, did the battery cable arc when you removed the cable from the battery with the key off. Even if something shorted out in the system it should not allow current to go through your bonding wire.

[doug@5rivers]

The circuit that is grounded is protected by the #7 30A fuse & is (Ign coil, injector, ECM, and IAC). I've removed and retightened every ground bolt I can find and unplugged all the large square plugs and eliminated the ECU and starter motor itself. My dealer is 3.5 hours away and my local dealers don't want to talk to me since I bought it elsewhere. I'm a fishing guide and the engine has about 210 hours on it and has been well maintained by me.

Yes, the negative cable arcs with the ignition turned off. I've tried 2 batteries with equal results.

[redlowrey]

The circuit that is grounded is protected by the #7 30A fuse & is (Ign coil, injector, ECM, and IAC). I've removed and retightened every ground bolt I can find and unplugged all the large square plugs and eliminated the ECU and starter motor itself. My dealer is 3.5 hours away and my local dealers don't want to talk to me since I bought it elsewhere. I'm a fishing guide and the engine has about 210 hours on it and has been well maintained by me.

Yes, the negative cable arcs with the ignition turned off. I've tried 2 batteries with equal results.

Check the main power relay, the main contacts may be stuck in the closed positon, even though you checked the grounds for tightness you still need to do a voltage drop test on them. If you remove the relay try touching the cable on the battery and see if it arcs.

[doug@5rivers]

Thanks for the replies. I took the boat back to the dealer and apparently there was some sort of issue from the rigging under the dash. They spent a bunch of time chasing it down but got it taken care of. I asked what they found but didn't get an answer. I took that to mean it was something that should have been done correctly the 1st time but wasn't.