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.<br />Any thoughts or suggestions on this one?<br />p.s. the only thing I've recently done is added a stainless prop, since the last time I ran it.<br />Thanks in advance<br /><br />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 ?<br /><br />BowriderBob<br />99 Vip 184<br />3.0L Mercruiser

 

[Trent]

Re: Mercruiser 3.0 blowing ignition fuses/alternator problem ?

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.

 

[bowriderbob]

Re: Mercruiser 3.0 blowing ignition fuses/alternator problem ?

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 !<br />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.<br /><br />Bowriderbob

 

[RandyJ]

Re: Mercruiser 3.0 blowing ignition fuses/alternator problem ?

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.

 

[sea wolf]

Re: Mercruiser 3.0 blowing ignition fuses/alternator problem ?

sounds like u got some water on a hot wire sonewhere when u sprayed the bilge. check all connections again. i think there's a product u can buy in an auto parts store that u spray on connections that will displace moisture. worth a shot.

 

[drewchips]

Re: Mercruiser 3.0 blowing ignition fuses/alternator problem ?

Did you ever find out what was wrong with this? I have the eact same thing happening with my '98 Volvo Penta SX engine. I sprayed out the bilge one year with a pressure washer as it had a lot of grease and grim. Ever since then it has had intermittent problems, occassionaly blowing the ignition fuse. I thought the parts in the engine compartment/bilge area could handle a few sprays of water from time to time. It is a boat that is subject to moisture from all sides, right?

 

[drewchips]

Re: Mercruiser 3.0 blowing ignition fuses/alternator problem ?

I figured out what happened here. Apparently the wiring harness that runs through the bilge area got some water on it and shorted the ignition switch off. I should probably look at having this harness sealed better but as long as I don't get it soaked I have no problems.

 

[dav56cg]

I am having a similar issue but with an added touch. The ignition fuse (10A) blows when returning the shift lever to neutral from either forward or reverse while the boat is in the water only. If I take it out of water I don't blow the ignition fuse. The boat is a 1996 stingray 556ZP with a merc 3.0 and alpha one gen two outdrive. I checked the neutral safety switch for any shorts and found none as well. Does anyone have any thoughts on this problem

 

[achris]

Please start your own thread, and not tag onto one that is 13 years old.

thread closed.