20amp blade fuse melting on shutoff

[jjmxhd]

Hey to all just joined this site after looking around on here a bit for a little info .so I've had this 95 crest sport pontoon for kver a year now never had a problem just completely redid all the furniture carpet flooring the whole deal. Was on the lake boat was running fine no indication of problem.went to pick up sister at marina and shut it off while waiting nothing no trim ignition checked battery cables and was tight as I could get with Finger don't care for the wing nuts.well the. Discovered 20amp fuse had blew changed it boat almost seemed flooded at this point unhooked fuel lines cranked it and chocked it actually started running without fuel line hooked up popped it back on took off up the lake for bout 20 minutes to clean it out. Got to a spot in a cove cut ignition then just for heck of it tried to start again had blew fuse again but this time melted it fuse holder and all.so after muttering cuss words and stripping wires for an hour repaired it enough to limp back to get back on trailer. So just cruising back with cowl off having friend watch and feel fuse Wich never seemed to get hot while running shut it off just to be safe to not over heat just sitting there and just starts melting jumped up and jerked negative wing nut off Wich was sizzling from my damn Fingers. At this point decided it wasn't safe had a friend tow us back. Went to local marine shop and they pointed me in direction of new voltage rectifier and switch box so I replaced both and bought a new used in great shape harness. Swapped everything out today and haven't tried putting power back on honestly kind of afraid of it melting just sitting there. Any advice would be appreciated and another note both battery wing nuts had wiggled loose and could be moves right before last melting of fuse before getting towed also inspected old harness for rubbed wires and didn't see any indication of it being in the harness. Thanks In Advance to any advice or suggestions I hate electrical issues

 

[jjmxhd]

Forgot to put engine.95 Mercury force 90hp

 

[GA_Boater]

Welcome aboard.

Throw those wingnuts overboard and get a couple of hexnuts.

The only way you'll know is by starting the motor. Speaking of motors - What in 'ell are you burning up?

 

[jjmxhd]

The main fuse on the outboard The 20amp blade fuse for the two red wires that run to the starter solenoid are the ones that melted on me but only up towards the fuse not near the solenoid

 

[jjmxhd]

It's just odd to me that it's doin this with the key off and engine not running but is all fine when running and engine dosent miss a beat while it's running it just all go nuts after the key is turned off took the Quicksilver control bkx apart that day on the water and gave it a quick glance over and didn't see any indication of wiring shorting out Wich if it was would make me think it would pop soon as ignition is turned not on shut off

 

[poconojoe]

Can it be the ignition key switch? Perhaps either the off position is shorted or there's a short somewhere within the switch during the motion of turning the switch.

 

[jjmxhd]

I thought about that I'll probably go ahead and just replace the switch to eliminate that possibility as well and the starter solenoid is only like 20 dollars so I'll probably replace that to and have my battery tested make sure some cells weren't shorting internally. I'll keep the post updated tho as I go thanks for the help and advice so far

 

[legalfee]

Here's a wiring diagram. It may help you figure it out.

 

[legalfee]

And here's the ignition switch:

 

[poconojoe]

And here's the ignition switch:

Ah, so there IS a ground incorporated into the ignition switch. I hope this is the problem because it would be such an easy and affordable fix. Good luck to the OP.

 

[dingbat]

Key switch is not capable of drawing down a 20 amp circuit. It's only function is the actuate slave side of the starting solenoid.

I would start off by first testing the starting solenoid to make sure it's not hanging up. You want a good solid "click" each time you actuate it.

Then move on to the starter. A short in the winding or a bad brush will do exactly as you describe.

And oh ya...a boat is no place for wings nutz. Replace hem with ny-loc nuts and throw the wing nutz as far as you can.

 

[legalfee]

Disconnect the battery and check for a short from fused +12V to ground using a digital ohm meter.. Any short on that circuit will blow the fuse.

 

[jjmxhd]

Ok I'll try that and test the solenoid and move on to the starter yea there gone already won't have wing nuts on anything of mine been meaning to do it this new boating season but only had it out twice before this little problem started I appreciate it guys

 

[jjmxhd]

Well got all my new parts in swapped starter out and ordered new solenoid along with switch box voltage rectifier and new wiring harness was putting the wire on from stud on solenoid to the starter and tightened it Down with a 1/4 inch ratchet and was not cranking down on it and noticed the stud in the solenoid was slightly spinning so I guess I'll be returning it and getting a replacement then should be ready to start it on the muffs and see what happens will keep posting the results if I could ever catch a break.

 

[jjmxhd]

Just gonna update everyone solved the problem red wire from ignition had got in a bind in the throttle assembly penched it and melted it.redid the wiring new connectors and solved the issue so just figured I'd let everyone know so if they ever have similar issue thanks for everyone's input and advice