Melting Fuses

[fowlerrudi]

Does anyone know what causes a fuse to melt? Not the element inside, but the plastic casing the surrounds the element itself. I have a 15 amp main fuse in it's 15 amp main socket. Seems to only happen when I serve the bike hot long suppers. High RPM over an extended amount of time. I have a new voltage regulator, new stator, new coils, new CDI. Just curious as to what makes a fuse swell like this and not blow. Thanks. -Rudi

[SPARKSS]

Does anyone know what causes a fuse to melt? Not the element inside, but the plastic casing the surrounds the element itself. I have a 15 amp main fuse in it's 15 amp main socket. Seems to only happen when I serve the bike hot long suppers. High RPM over an extended amount of time. I have a new voltage regulator, new stator, new coils, new CDI. Just curious as to what makes a fuse swell like this and not blow. Thanks. -Rudi

Howdy Rudi......This is going to sound stupid but "heat" is your problem not over-current. When you say "plastic" I'm guessing that you're probably talking about an ATO/ATC type fuse with 1/4" male tabs. When the socket (more particularly the female metal part) gets weak, with significant current (increasing somewhat with engine speed) , what happens is that the voltage drop across this fuse-to-socket increases. From there ohm's law tells the story ....power dissipated at this point due to the resistance incurred by the voltage drop and the current flowing through that resistance = heat - which is what swelled or melted your fuse. I see it all the time in other equipment I work on.

This degradation is a downward spiral by the way.......a little heat initially makes the socket weak = more heat......weaker still......surrounding support plastic melts.....eventually something burns right up and yet the load and external wiring may be just fine. The repair is to replace the affected parts, check the current and go from there (maybe upgrade these parts etc).

[Calvin Blackmore]

So is this corrosion in the sockets causing this?
I have never seen a fuse melt before.

Is the only option to replace the fuse panel? or can one be salvaged with contact cleaner and tlc?

[Steve]

[-o<Sparkss is absolutely correct \\/, heat is the problem. Now for your challenge...find the source of the heat.

Electrically, the only thing that creates heat is resistance. In your case, I would start with the fuse contacts. Is the the standard cylindrical glass fuse on the bike, or something that has been added? Either way, clean the contacts. Even if they look clean, use some very fine emery cloth or sandpaper and some contact cleaner spray. Look behind the fuse mount to make sure the wire attachment is good. Sometimes the wires are soldered to tabs, sometimes they are riveted. Squeeze the rivets to make sure they are tight. Or you can scrape a clean spot on each side of the connection and solder it to assure a good connection.

If there is just the slightest gap in the connection (a layer of oxidation?), the only way electricity is going to get across is to jump. This will be in the form of an arc. Ever notice how hot an arc welder gets? :shock: You just might have a tiny, little 14-amp arc welder happening in your fuse contacts. :-({|=



.

[SPARKSS]

So is this corrosion in the sockets causing this?
I have never seen a fuse melt before.

Is the only option to replace the fuse panel? or can one be salvaged with contact cleaner and tlc?

Corrosion can surely start this happening.......once the heat starts to weaken the female socket it degrades as I detailed. You can improve the situation or prolong the usefullness by removing the contact itself......cleaning and then carefully (!) bending the tang and/or sides as applicable so as to increase the tension to the fuse. Once the plastic surrounding all this starts to melt however, this allows more movement to take place which aggravates the situation once again. Your comfort level with failure and repair will dictate how you'll likely proceed from here!

Melted blade type (ATO/ATC) type fuses and holders......I've seen a ton of 'em.

[Road_Clam]

Does anyone know what causes a fuse to melt? Not the element inside, but the plastic casing the surrounds the element itself. I have a 15 amp main fuse in it's 15 amp main socket. Seems to only happen when I serve the bike hot long suppers. High RPM over an extended amount of time. I have a new voltage regulator, new stator, new coils, new CDI. Just curious as to what makes a fuse swell like this and not blow. Thanks. -Rudi

Corrosion is the #1 culprit for melted electrical components. Battery acid vapor causes a lot of corrosion issues in the GS's. Here is my experience with some melted electrical connectors:

http://www.thegsresources.com/_forum/showthread.php?t=105528&highlight=short

[Lonthemon]

I once had the same fuse melting problem. It was due to extra current needed to supply the aftermarket fairing and saddle bag lights. Installing a headlight relay kit solved my problem. I bet your melting fuse is the headlight fuse.