Reply
 
Thread Tools Search this Thread
 
Old 19 December 2009, 23:19   #1
Member
 
Country: New Zealand
Town: Tauranga
Boat name: Extra Pleasure
Make: Atomix
Length: 5m +
Engine: Outboard 60HP 2Strke
Join Date: Aug 2009
Posts: 182
Main engine fuse blows... sometimes

Seems like I'm posting a lot of 'help' posts on here!! My Rib's not all that bad!!!

Anyway, My Mercury 60Hp 2 Stroke has started blowing the odd fuse -- the main outboard blade fuse (20Amps)...

It's quite tricky to debug as it only happens sometimes... but what I do know is this:

It doesn't blow whilst travelling along, or fiddling with any other electronics (radio etc etc).

It blows somewhere between cutting off the engine and then trying to crank it again -- basically, when you've been for a spin, anchor up, go for a dive and then are ready to head back in, engine won't start and you notice fuse has gone...

So common sense tells me it's blowing when I'm trying to restart the engine (can't see it blowing on shut off...)

But I've never been able to recreate it when I want to test it... the other day it blew twice (we stopped twice), but then on my last trip, it blew after/at our first stop, but never again (2 more stops followed).

I know this is a complete stab in the preverbial dark, but where would you recommend I start looking for culprits? Could it still be related to other electrical items (radio, gps, stereo), or does the evidence point to something enginey?

I've read elsewhere that a shorten solenoid would blow the fuse on start, but I know little more about that than that...! And as mentioned, it's not all the time... just when it fancies a bit of attention...

Thanks heaps in advance
__________________

__________________
rjbathgate is offline   Reply With Quote
Old 20 December 2009, 03:24   #2
RIBnet supporter
 
Jizm's Avatar
 
Country: UK - England
Town: Southampton
Boat name: Hissing Sid
Make: Ross Smith Cobra
Length: 6m +
Engine: 200HP Optimax
MMSI: 235038046
Join Date: Jun 2002
Posts: 3,803
Quote:
Originally Posted by rjbathgate View Post

I've read elsewhere that a shorten solenoid would blow the fuse on start, but I know little more about that than that...!
It's a good place to start, get the meter out and check thhrough the start circuit, have a wiggle on a few cables and check the general state of the wiring. You could eliminate the electronic units by dis-connecting them completely. Just an idea.
__________________

Jizm is offline   Reply With Quote
Old 21 December 2009, 04:15   #3
Member
 
Country: UK - Scotland
Boat name: Wildheart
Make: Humber/Delta Seasafe
Length: 5m +
Engine: Merc 60 Clamshell
MMSI: 235068449
Join Date: Apr 2007
Posts: 4,610
When it;s popped, does it show any signs of life before nothing happens? (e.g do you get your warning buzzers / can you hear the remote choke clicking kind of thing?) That would confirm it's not blowing on shutdown. If that all behaves normally, and when you turn the key absolutely nothing happens, that would hint you ainly getting juice to the starter.


I'd suggest the "meter over the solenoid" is probably a good place to start. Another way to test it might be to disconnect the big juice cable from solenoid to stareter (at the solenoid end so you donlt have a live cable waving about) turn the key & see what happens - if it pops the fuse without the starter, then you;ve found the problem.

Might also be wirth going through the remotes with a meter - The witring in there isn't infallable......

Assuming it's PT, and of a certain age, I think your trim solenoids should be the same as the starter one (swap to test it).
__________________
9D280 is offline   Reply With Quote
Old 21 December 2009, 04:47   #4
Member
 
Country: New Zealand
Town: Tauranga
Boat name: Extra Pleasure
Make: Atomix
Length: 5m +
Engine: Outboard 60HP 2Strke
Join Date: Aug 2009
Posts: 182
Quote:
Originally Posted by 9D280 View Post
When it;s popped, does it show any signs of life before nothing happens? (e.g do you get your warning buzzers / can you hear the remote choke clicking kind of thing?) That would confirm it's not blowing on shutdown.
No alarms, buzzers or clicks than I can tell... when fuse is gone and i turn key, nothing at all, complete silence... especially on the faces of the people on board ha!!

Borrowing a multimeter tomorrow - will get probing and testing... and try and find the solenoid!!
__________________
rjbathgate is offline   Reply With Quote
Old 21 December 2009, 06:09   #5
Member
 
Country: UK - Scotland
Boat name: Wildheart
Make: Humber/Delta Seasafe
Length: 5m +
Engine: Merc 60 Clamshell
MMSI: 235068449
Join Date: Apr 2007
Posts: 4,610
Maybe I should have been more explicit - next time it happens, don't go straight to "crank" position with the key, set it to "run" & see what happens (i.e can you hear the choke solenoid if you hit the choke kind of thing)

Not all engines buzz on start - I was trying to be overly general. If it normally does, that might hint it's happening on power down.
__________________
9D280 is offline   Reply With Quote
Old 21 December 2009, 09:52   #6
Member
 
Country: UK - Scotland
Town: Ardfern
Boat name: Moon Raker
Make: Humber Destroyer
Length: 5m +
Engine: Honda BF 90 D
MMSI: 235035994
Join Date: May 2006
Posts: 694
In view of my experience during the summer, I wonder if you have a problem with the regulator/rectifier. Is there a smell of hot insulation near it? The main fuse blew on my engine - not surprising really as the rectifier sprayed a jet of molten metal over the engine block. This wasn't obvious until I unbolted the regulator and looked at the back of it.
__________________
alystra is offline   Reply With Quote
Old 21 December 2009, 15:16   #7
Member
 
Country: UK - Scotland
Town: Inverkip / Angola
Boat name: Mach a Seo
Make: Princess
Length: 10m +
Engine: diesel
Join Date: Feb 2007
Posts: 61
It Worked for Me!

I had the same thing a few years ago on mariner 150, couldn't get to the bottom of it, had me flumoxed!

Eventually traced it to a bared wire in the for the trim and tilt switch in the control box.

The break in the insulation was down near the pivot point and every now and then it would short out blowing the fuse, when you went into neutral. You wouldn't know until you went to start the engine again as it kept running with the fuse blown, or if you were lucky you'd notice if you tried to adjust the trim.

Worth a try.

Cheers.
__________________
I must go down to the sea again to the lonely sea and the sky
All I ask is a tall ship and a star to steer her by
the wheels kick and the winds song and the white sails shaking
a grey mist on the seas face and grey dawn breaking
Roger Barr is offline   Reply With Quote
Old 21 December 2009, 15:27   #8
Member
 
Country: New Zealand
Town: Tauranga
Boat name: Extra Pleasure
Make: Atomix
Length: 5m +
Engine: Outboard 60HP 2Strke
Join Date: Aug 2009
Posts: 182
Quote:
Originally Posted by Roger Barr View Post
trim and tilt switch in the control box.
Silly question, but where would this be?

Cheers
__________________
rjbathgate is offline   Reply With Quote
Old 22 December 2009, 00:30   #9
Member
 
Country: New Zealand
Town: Tauranga
Boat name: Extra Pleasure
Make: Atomix
Length: 5m +
Engine: Outboard 60HP 2Strke
Join Date: Aug 2009
Posts: 182
Hey

Righty, I have just:

completely cleaned, checked and tightened main battery terminals (although they were pretty good already)

cleaned excess gunk/grease/oil from what cables/connections in engine I can


I have a question... in order to check wire connections by 'wiggling' them all, don't i need the key in crank/start position in order to juice up all the connections to engine? And as such, if I have someone hold the key in crank/ignition, the engine is gonna start, and then constantly be on crank -- isn't that bad for the engine?!

Going out again tomorrow so will see if it happens again... it's just annoying that I haven't found an obvious cause... id just like to know what's causing it arrrgghhhhh!!!!



Cheers
__________________
rjbathgate is offline   Reply With Quote
Old 22 December 2009, 04:17   #10
RIBnet admin team
 
Poly's Avatar
 
Country: UK - Scotland
Boat name: imposter
Make: FunYak
Length: 3m +
Engine: 2 stroke YAM 20 HP
MMSI: 235089819
Join Date: Sep 2005
Posts: 10,112
Quote:
Originally Posted by rjbathgate View Post
I have a question... in order to check wire connections by 'wiggling' them all, don't i need the key in crank/start position in order to juice up all the connections to engine? And as such, if I have someone hold the key in crank/ignition, the engine is gonna start, and then constantly be on crank -- isn't that bad for the engine?!
You can check for a short with e.g. a multimeter. Only the starter motor cables need the key at 'crank' to be 'energised' the rest should be 'live' with the key at 'run'
__________________
Poly is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 02:52.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.