When fuse clips are loose

[Darthomas]

Heavy rain last night on way home from work, ran the defroster.
No fan this morning.
Hmph! Long time since this happened,
but I already knew what it had to be.
Load side fuse clip was a bit loose.
This is what happens when heat builds up at the end of a fuse.
I think I've only ever seen this on heater/fan fuses in my cars.
Note that the link is not parted.
Always squeeze clips tighter when replacing fuses.
Heat will always cause them to weaken in time.
Old timers know, but new guys might not.

 

[shorty64]

good tip/reminder! helps if the clips are clean as well, ie not excessively rusted.

 

[moparedtn]

These old Buss type fuses are weird critters for sure.
I spent a couple hours yesterday chasing a problem where my interior lights stopped working. All manner of switches, sockets, bulbs were checked. Even dropped the fuse box and checked all the connections in back of it.
Fuse for the "cigar lighter/dome light" checked good for continuity on my meter.
Drove me nuts. Gave up, went inside to cool off (it reached 100F yesterday!).

Went back out after dark and took a pair of needle nose pliers and jumped the fuse.
Lights came right on.
How the heck is the fuse checking good (I removed it to check it), yet not good?

Follow up 7/26/16:
Had to go to 2 auto parts stores around here to find replacement AGC type fuses. Popped in a new 20 amp and all is well again.

 

[Darthomas]

good tip/reminder! helps if the clips are clean as well, ie not excessively rusted.

The more current in circuit, the more likely to oxidize to blue and/or rust.
Yup, roll fine sandpaper into a fuse sized cylinder, and spin it inside the clip.

 

[Darthomas]

Measured a fuse last night at work in an embedded computer/operator interface.
Measured good.
Took out the power supply and measured same thing at circuit board, no good!
Loose clip! Fixed that, but the switching type power supply would only make occasional clucks, not really start running.
Left a msg to boss, start repairing supply, or replace for $65?

 

[Ranger16]

Only once have I had a glass buss fuse blow and not show through the glass. It was only a year or so ago. The only way I found it was by a continuity test with a DVM.