A strange series of events.......

[wetskier2000]

1997 Ski Nautique, GT40, 1500 hours... Left the radio on the last time out. Presume that killed the battery. jumped it and it grudgingly started but the idle was crappy. ran it a couple miles up and down river, idle still crappy, dies then won't restart. Nothing at the key or dash... Dead, no horn, no crank, no bilge pump, nothing... get towed in... swap in a battery, nothing... find the 60 amp breaker near the ECM tripped. reset it, the engine cranks and the dash comes alive... engine won't fire, I do not her the fuel pumps.. swap ECM, no luck, swap relays, nothing.... Next I'll check the fuel pressure so I know if it's spark or fuel.... any ideas???

[NautiqueJeff]

I had a GT-40 that did that once. It ended up being corrosion on the plugs on the backside of the dash, believe it or not! I'd check the ignition switch too. Your run circuit may be corroded.

There are plenty of other things that could cause this too, but those are the ones that got me.

[wetskier2000]

I think the under dash cleaning is probably a good idea and I have not done it in a while... I'm skeptical that's my root problem... I tried to verify fuel pressure, but my tester doesn't seem to like the GT40 Schrader valve. I get nothing on the gauge despite a nice spray of fuel.... Something special about the fitting on the PCM engine? At key on, I did not hear the fuel pumps, so I jumped them directly to 12+ and they come on but still crank but no start. I pulled a plug and grounded the body, but seem to get no spark...

[wetskier2000]

Ok, I found it.... kinda.... I swapped some of the typical parts (relays and known good ECM) still nothing... No spark and no fuel... I scratch certain body parts a bit and think to myself.... sure I could have an ignition system failure and a fuel system failure... but at the same time??? Seems unlikely.... well, the ECM is controlling all that, maybe it's just not getting power... I poke around at the 60, 15 and 12.5 breakers on the panel beside the ECM. I get power on the 60 (obviously since it went from no crank to crank when I reset that one the other day).... I seem to get nothing on the 15 and 12.5.... I clean the red insulation off the 15 so I know I'm making contact and sure enough no power on either post. I jumper the 15 to the starter relay battery lug just below it, turn the key and hear the fuel pumps.... I turn the key to start and the GT40 fires up!!! Now I need to find out why that 15 is getting no power... Is there some fuse for that somewhere???

[wetskier2000]

Appears the 50 amp fuse in the battery box feeds the 15 amp circuit breaker... I monkey around with that a bit and then get power to the 15 amp CB. The motor fires up... The fuse holder itself seems wonky... I'll look for another.... any ideas on this??

[gary s]

Page 282 section 6-8 has that info but in looking for it myself I see you found it. I believe there was a recall? or service bulletin removing that fuse and moving that lead over to the starter to eliminate most of that wire as well. It's over on CCF but unfortunately with the site down good luck finding it. https://www.planetnautique.com/Corre...e%20Manual.pdf

[gary s]

I'm thinking that fuse gets removed and the lead goes to power side of the starter mounted solenoid and then that circuit is protected by the 60 amp breaker instead of a remote out of the way 50 amp fuse

[wetskier2000]

without knowing the implications of adding 15 amps to the existing 60 amp circuit, I'm thinking new inline 50 amp fuse from the starter solenoid lug directly to the 15 amp breaker. eliminate the line from the battery to the 15 amp breaker.

[wetskier2000]

.....makes me wonder if replacing the ECM a couple years ago was REALLY the root problem....

[wetskier2000]

We skied last night!! I wired an inline 50 amp fuse between the starter solenoid lug and the 15 amp breaker and removed the line from the battery to the 15 amp breaker as well as disconnecting it from the battery. The motor would not start. I checked the 12.5 amp breaker and saw no power so I jumpered from the 15 to the 12.5 and the GT40 fired up... The wiring diagram would not have lead to me to believe that both the 15 and the 12.5 had the same source... mea culpa...

[Fast351]

I've had some electrical problems with my boat too. I realize that boats are not built in the same volumes as cars so they never get a real opportunity to sort out the best way to wire things and build standard wiring harnesses, but good lord these boats look like they were wired by a 4th grader.

I sure hope that the newer boats with all the computerized crap have better engineering behind the wiring, otherwise I weep for the future 10 years from now when those start having electrical gremlins.