Checking the grounding

[supervol0509]

Can anyone give me a quick "How to" on this? We've had a couple of issues with our boat, and I'd like to check it out myself, but don't know where to start.

[sivs1]

By checking grounding I'm guessing you mean the negative lead from your battery. I am sure your 03 is somewhat similar to my 06 in regards to where wires connect. First both positive and negative connect to the engine on the left side, open up your left rear locker and you'll see both the red and black connecting right in the middle of the engine towards the bottom, make sure those connections are tight. If all good make sure battery(s) connections are tight. Need more details after that, do you have dual batteries on a switch? check connections at the switch, do you have distribution blocks installed? check those connections. Basically go through everything and just make sure all connections are tight and then we can go from there.

[supervol0509]

From everything I read, I am getting that everything is grounded to the engine block. Looks like the positive from the battery cable goes to the starter solenoid. I will have to trace the negative, as I didn't see where it was connected. We are having problems getting the boat started, so trying to check all wiring connections to starter solenoid, plus grounding, battery connections, etc. I was reading through my shop manual last night, and various tests of the ignition system talk about the ground connection, but not sure what I am looking for. Are the lights, stereo, bilge pump, etc. also tied to the same ground. If so, are they tied to it back through the battery?

[MLA]

From everything I read, I am getting that everything is grounded to the engine block. Looks like the positive from the battery cable goes to the starter solenoid. I will have to trace the negative, as I didn't see where it was connected. We are having problems getting the boat started, so trying to check all wiring connections to starter solenoid, plus grounding, battery connections, etc. I was reading through my shop manual last night, and various tests of the ignition system talk about the ground connection, but not sure what I am looking for. Are the lights, stereo, bilge pump, etc. also tied to the same ground. If so, are they tied to it back through the battery?

Since the engine block is the only ground plane on a boat, as well as the point where the 12V circuit is completed through the alternator, yes, all grounds do lead back to the block electrically, but not physically. You have a large cable that will connect the battery to the engine block. You will also have other smaller grounds that are connected to ground BUS bars through out the boat. From there, all the component grounds terminate to the BUSs. Not many components home run all the way to the battery.

The best way to check the ground cables, is to use a DVOM and doa voltage drop test.

Will the boat not crank or not start? Completely different paths of diagnostics.

If you are having multiple problems, start simple and look for things in common.

[supervol0509]

I have nav lights tripping the breaker. This problem needs to be fixed, but is not urgent.

The bigger problem is the intermittent operation of the starter. At times, it is not engaging. Other times it is fine. I was told to check the connecting wires and ground, first. I was also told to connect a light to the positive at the starter, and the other at the ground. I just connected it between the positive at the starter, and the negative at the battery. Light stays lit up all the time, and draws too much power from circuit to full engage the starter. Not accomplishing what the poster was getting at, I don't think.

[MLA]

Ok, so the starter does not always crank. When you say "doesn't engage", can you clarify? Is the starter doing nothing or does it sound like the starter motor spins, just doesnt engage the flywheel?

A 12V test light can be a valuable tool in this case, just be aware of exactly what circuit you are probing. Those 3A incandescent bulbs can let the smoke out of a PCB.

[jstenger]

There should be a large ground wire going directly to the engine block. There should be a smaller ground wire going directly to the drivers area.