Melted fuse
04-13-2008, 03:18 PM
#16
Rennlist Member
Thread Starter
thanks for the tutorial Alan. Here is a link to a prior thread with a picture showing my ce panel and the fuse block I need to replace, due to the fog light fuse burning the slot in the panel: https://rennlist.com/forums/928-forum/419880-bizzare-wire-connection.html
If I bought a new fuse block from you, would it be a direct fit into that location? I assume I would need to plug the wires back in from behind. I also assume I would likely just destroy the bad fuse block upon removal, and the good one would just pop in?
Of course, I still don't know what caused the fuse to burn. Had it checked, and there were no shorts in the wiring. Maybe too strong of a bulb in the foglights?
If I bought a new fuse block from you, would it be a direct fit into that location? I assume I would need to plug the wires back in from behind. I also assume I would likely just destroy the bad fuse block upon removal, and the good one would just pop in?
Of course, I still don't know what caused the fuse to burn. Had it checked, and there were no shorts in the wiring. Maybe too strong of a bulb in the foglights?
04-13-2008, 09:11 PM
#17
Electron Wrangler
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Ed,
Too high a wattage bulb can be a factor - but its not due to a short - that would just blow the fuse instantly. The most common cause is oxidation/corrosion of the fuseholder or fuse blade contacts. Higher current will then hasten issues. Increased contact resistance causes heat at the connection and heat causes faster degradation causing higher resistance & more heat... The heat is conducted up the blade & melts the fuse encapsulation - it also heats the fuseholder - but this is slightly more robust than the fuse.
Another factor that leads to poor contacts is excessive mechanical wear - maybe too may insertions and especially anything that expands the fuseholder contacts like plugging anything but a fuse into it...
I do not encourage lots of fuse adjustments except where there is clear need for cleaning or replacement - if the contacts already have corrosion - chemical or light mechanical cleaning is the best remedy short of replacement...
Your other assumptions are all correct...
Alan
Too high a wattage bulb can be a factor - but its not due to a short - that would just blow the fuse instantly. The most common cause is oxidation/corrosion of the fuseholder or fuse blade contacts. Higher current will then hasten issues. Increased contact resistance causes heat at the connection and heat causes faster degradation causing higher resistance & more heat... The heat is conducted up the blade & melts the fuse encapsulation - it also heats the fuseholder - but this is slightly more robust than the fuse.
Another factor that leads to poor contacts is excessive mechanical wear - maybe too may insertions and especially anything that expands the fuseholder contacts like plugging anything but a fuse into it...
I do not encourage lots of fuse adjustments except where there is clear need for cleaning or replacement - if the contacts already have corrosion - chemical or light mechanical cleaning is the best remedy short of replacement...
Your other assumptions are all correct...
Alan
04-14-2008, 12:12 AM
#18
Rennlist Member
Thread Starter
I was able to disassemble the spare ce panel, and recover pretty much intact spare fuse blocks, relay blocks, and harness receptors, plus extra relays and fuses - thanks to Alan's good write up!
Must have very small tools - flatblades and hooks, in order to avoid breaking those little tabs holding everything together.
The donor board also gave me a good understanding of how it all works. For instance, the contact blades in the fuse blocks are arranged in a certian order (and they will fly out upon disassmebly if you are not careful
).
The next step is to pull my good ce panel out and do the full R&R per Sharkskin's excellent write up. I should be able to fix my burned fuse block and get foglights back....(and avoid a footwell fire!)
Must have very small tools - flatblades and hooks, in order to avoid breaking those little tabs holding everything together.The donor board also gave me a good understanding of how it all works. For instance, the contact blades in the fuse blocks are arranged in a certian order (and they will fly out upon disassmebly if you are not careful
).The next step is to pull my good ce panel out and do the full R&R per Sharkskin's excellent write up. I should be able to fix my burned fuse block and get foglights back....(and avoid a footwell fire!)
