Slow blowing fuse

[machinest]

On my bike the main fuse has been sort of half blowing ,that is it will melt the solder out of the ends and then intermittently have the wire inside come in and out of contact with the engine vibration .This causes the engine to miss and back fire.
I just rechecked the charging system and it seems to be in spec according to the stator papers. Replacing the fuse will deal with the problem for a week or two but it happens again (3rd fuse so far ).
Thinking of putting in relays and separate fuses for the headlight as it is the last heavy load on the original wiring
Any one have any idea about this.

[Texas Don]

I once had a heater blower in an old chevy that I drove in my youth that would do this. Only in the winter of course when I needed it. I would replace the fuse only to have the replacement do it again in a very short time. Turned out to be a bad box of fuses if you can believe that. Once I used the last one in that box and purchased a new lot, the problem resolved itself.
Have you tried a different lot of fuses? The current draw in your circuit should not be enough to unsolder the fuse wire without blowing the fuse.
Don

[machinest]

First fuse was original (at least to me ) but the two others were from the same box.

[chef1366]

Do the dance. Clean connections and grounds. Might be ignition switch related.

[BassCliff]

Hi,

Yes, it sounds like heat caused by corroded, dirty connections rather than a short circuit pulling more current. That's why the fuse is melting rather than blowing. Check and clean the entire wiring harness, all connections and grounds, from headlight bucket to the tail light including the fusebox and ignition switch. Check the "Electrical Odds and Ends" section for cleaning/repair information. Keep us informed.


Thank you for your indulgence,

BassCliff

[machinest]

OK just did the contact cleaner and dielectric grease thing from back to front . Will see if the problem reoccurs ,looks like this may have to become a spring ritual until I Get a garage for winter storage.
I'm off to the local ice cream stand as it is hot and muggy here

[OldVet66]

If you brighten up all the contact points inside and outside the dielectric compound should keep it from building up a high contact resistance for a good long time. Contact cleaner alone might not be enough. A miniature spiral brass brush small enough for the barrels might be in order. That greenish patina needs to go away.

[machinest]

Used a scotch bright Qtip from work , works well for getting the inside of the barrels clean.

[BassCliff]

Hi,

I like little wire brushes too, and sometimes sandpaper, to clean electrical connections. Naval Jelly, De-Oxit are good cleaners. See the "Electrical Odds and Ends" section on my website for more ideas.


Thank you for your indulgence,

BassCliff

[reddirtrider]

Just to clarify, fuses are thermal devices - they all melt.

One other nick nack. Since they are thermal devices, they tend to open up (melt) more in the summer due to the higher ambient temperature.