Grounding Problem

[linebacker55]

New guy here, been browsing for a while, but first post. My 2002 SAN has a ground. I can't find it, was wondering if anyone has experienced this or knows of common ground locations. Boat ran fine all year last year, put away for winter late October. Got out today, engine cranks but won't fire. Start digging around, find problem to be no fuel to engine. Look farther, find a blown fuse. Fuse is in the block of 3 fuses right next to the ECM. Replaced fuse, turned master switch to on, punched in code, pushed start. Now the keypad is in 'standby'(i don't know the proper term for that condition), push start again and second light comes on and you are ready to start engine. This is where the fuse blows. I can hear it blow as soon as i push the start button. Not sure if it is in the ignition switch, or fuel pump wiring, or ECM. Anyone got a wiring diagram? I am not too good at troubleshooting these types of things, but don't particulary want to pay someone to do it, either. Arghhh!!! I am so frustrated. Thanks for your time.

[linebacker55]

RE: Grounding Problem

Sorry it is the PCM Excalibur engine.

[NautiqueJeff]

RE: Grounding Problem

This diagram should be close. It is from a 2004, but should be fairly accurate for your boat as well.

http://www.planetnautique.com/Correc...ingHarness.pdf

[linebacker55]

RE: Grounding Problem

Thanks Jeff, i am headed out with the multimeter and a plan...we shall see how it works... :|

[Flux]

RE: Grounding Problem

I am pretty sure all the ground wires on the motor are grounded to the motor. If I recall correctly, there are grounds on both sides of the engine toward the bow and another that attaches to the aluminum frame on one side. check that out for yourself. It's fairly simple to trace the wires.

Couple things. When you key in your code and hit start, it simply powers everything up. Tapping start will cycle the fuel pumps and put power to the gauges. Holding start will do the same as tapping and also fire the starter.

Not sure if you have a bad ground, sounds more like a short. No ground would not blow a fuse I don't think, it would simply make nothing happen. Kind of guessing a bit, but it's a 12 volt neg ground system.

I would first just look over all the connections you can see and look for loose wires or frayed connections etc. Then trace that fuses power wire to the component(s) it serves. A bad motor in a fuel pump could pop a fuse.

If you can get your hands on the Excalibur parts manual it might tell you what the fuse is, but I am not sure. Best of luck.

[linebacker55]

RE: Grounding Problem

I think i am narrowing it down, probably a bad fuel pump. If pump is stuck(bearing seizure), the motor would draw a ton of amps, because it would generate no countervoltage, therefore huge current flow, therefore blown fuse. Gotta go do some more troubleshooting. Thanks for the inputs.

Anyone know if a bad fuel pump relay would cause a current spike? Or would it just prevent the motor from getting power?

[Flux]

RE: Grounding Problem

You could simply disconnect the power wires to the fuel pump and turn it over just to see if that is the culprit. You have the low pressure pump in the tank and the high pressure pump in the fuel control module.

I'd say that if you are tapping the start switch with the boat on and the fuse is popping immediately, it's probably one of the fuel pumps. Boat won't start unless you hold the button down. I know that both pumps cycle when you tap the start, I heard them going on mine when we got her in shape for our first weekend out.

[linebacker55]

RE: Grounding Problem

My LP pump is right next to the HP pump/filter/water seperator thing. Just took it off, after disconnecting it electrically i turned on/off without cranking engine 5 times and fuse didn't blow. Cranked engine once ran for a couple of sec and i killed it, but no blown fuse. I think i found my problem. Thanks to everyone. :grin: