2004 Cobalt 200 quit on Lake.

[Dizel8]

So there I was!

Anyway, was out on the boat having a great time when the boat just flat out quit, no hiccups or anything, just stopped dead in the water. Turning the ignition key had zero effect. All accessories was working on own individual switches, ie nav, bilge, blower.

Got a tow to slip.

Went back next day and found two blade fuses burnt on engine fuse box, F1and F2, ignition, dash and accessories. Replaced them, but they immediately burned when going to start.

Mechanic then ran engine on his harness, no problem. Plugged boat back into own harness, burned breakers again. Looked all under dash, moved wires, but found no shorts. Stated boat then started normally and no further problems on test run. Mechanic is not really happy because he never found the real problem, but conversely doesn’t want to start replacing all the wires.

So my question to y’all is what could be the problem and how would you proceed?

[Sublimecat]

Did the fuses burn with the key in the run position or start position or do you know? That would help to understand what part of the circuit to troubleshoot. It sounds like you have a wire that was shorted to ground and now that it’s been moved it’s no longer grounded out. Look for chaffed wires sitting on metal edges.

It’s rare electrical problems heal themselves.

[Dizel8]

Did the fuses burn with the key in the run position or start position or do you know? That would help to understand what part of the circuit to troubleshoot. It sounds like you have a wire that was shorted to ground and now that it’s been moved it’s no longer grounded out. Look for chaffed wires sitting on metal edges.

It’s rare electrical problems heal themselves.

First of thanks for responding.

On the the lake they were in run, when I changed them, they blew going to start. Looking under dash nothing appears chafed or darkened. As for your last line, I completely agree and that’s what worries me, clearly something is wrong.

[akorcovelos]

No easy way to do it, gotta start at one end and work to the opposite end until you find the short. Crappy answer, but electrical fire on a boat is no fun, trust me. You know the two circuits to trace, start at the fuse and work back to the helm.

[Dizel8]

No easy way to do it, gotta start at one end and work to the opposite end until you find the short. Crappy answer, but electrical fire on a boat is no fun, trust me. You know the two circuits to trace, start at the fuse and work back to the helm.

All answers are appreciated, even if they involve crappy work:)

[jhnmdahl]

The cheap way to do it is get one of those continuity testers that beeps and hook it across where the fuse goes and start jostling things around until you hear a tone. The expensive way is to order a new ignition switch, etc, and keep throwing parts at it until the problem goes away. A surprising number of people take the second route.

John

[Bfun220]

What he said.

[Dizel8]

The cheap way to do it is get one of those continuity testers that beeps and hook it across where the fuse goes and start jostling things around until you hear a tone. The expensive way is to order a new ignition switch, etc, and keep throwing parts at it until the problem goes away. A surprising number of people take the second route.

John

It’s, as you can all imagine, among the most annoying things in the world.

Traced most the wiring, physically and with a tester. Found nothing so far. Took the boat out and ran great, but as others have said, shorts doesn’t disappear, they lay in wait.

[Dizel8]

So sadly the problem still persist, thought I had it beat, but apparently not.

Anyone have the actual wiring diagram, ie the shop one?