Mercruiser 3.0 blowing ignition fuses/alternator problem ?

bowriderbob	Ok guys, this is a weird one (for me, anyway). My Mercruiser 3.0L has always ran great. Tonight, we take it out, and it starts fine and then immediately quits. I go to restart, and there is nothing happening when I turn the key, and all the gauges on the instrument cluster are dead. I check the fuse block, and find that the fuse is blown for the ignition (?, it's a 25 amp fuse, and has a large wire coming off of it). I replaced the fuse, and as soon as I turn the key on, it blows again. Any thoughts or suggestions on this one? p.s. the only thing I've recently done is added a stainless prop, since the last time I ran it. Thanks in advance update: I disconnected the leads on the alternator, replaced the fuse, and the boat started and ran fine on several attempts. I replaced the leads, and still no problems. Is this a bad connection in the leads, or alternator or regulator going bad ? BowriderBob 99 Vip 184 3.0L Mercruiser	2002-07-20
Trent Crawford	If it were me.. The first thing I would check is the alternator. Remove all wires and tape up connections. Replace fuse and see if it happens again. Also look for wires broken or rubbing.	2002-07-20
bowriderbob	Ok, I can't seem to find any broken or rubbing wires. I took the boat out yesterday, and just going to about 1/2 down the cove, and there it goes again with the fuse.Had to get towed back in, Thank you to that old jon boat out for fishing ! I had lightly sprayed out the bilge area to get out some debris, (in retrospect, probably not a good idea), and am thinking that maybe some water got on a wire it shouldn't and is causing a short. The boat has ran great up until now, so I'm having a tough time figuring it out. Bowriderbob	2002-07-22
RandyJ	Hmmmm... If your alternator is charging it is probably okay. Definitely sounds like you have a short in the system somewhere. You could disconnect your battery and use an ohm meter to check one circuit at a time for a short to ground. Just a suggestion. I've solved a few problems that way.	2002-07-23
sea wolf	Sounds like you got some water on a hot wire sonewhere when you sprayed the bilge. check all connections again. I think there's a product you can buy in an auto parts store that you spray on connections that will displace moisture. Worth a shot.	2002-07-23

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