EGI fuse HOT! literally
11-09-06, 02:05 AM
#1
Rotary No Ka Oi
Thread Starter
EGI fuse HOT! litterally
Well I went to pull the EGI fuse the other day and noticed it had been fried. The fuse itself was intact but the plastic houseing was melted on one side. I got off work late and couldnt buy a new one so at work I went to pull it again, except this time I actually burnt myself on it, and ended up dropping/throwing it when it burnt me. When it came time to leave work I attempted to use the 30A fuse from the retractor so I could get home, however its touchy. It will be on for awhile, then back off. I found a sort of sweet spot where it has been staying on but the "new fuse" is heating up as well. The other fuses in the box are fine, and are normal temperature.
What could be cause this fuse to get so hot, yet not blow the fuse? Any advice would be greatly appretiated. Mahalo.
What could be cause this fuse to get so hot, yet not blow the fuse? Any advice would be greatly appretiated. Mahalo.
11-09-06, 07:45 PM
#3
Rotary No Ka Oi
Thread Starter
Well the terminal looks good as far as I can see. The clip on the bottom of the fuse box though looks like it may have gotten melted to. Im really not sure where to start.
11-11-06, 06:27 AM
#5
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Wish I could help I blow them at random. I suggest if its an S4 taking a look at the wires near the passenger side headlamp. Possibly the junction of the wiring feeding the fuse block also may be a souce of high resistance (ie Corrosion).
11-11-06, 08:11 AM
#6
The mystery of the prize.
I imagine you are probably drawing too much current through it, generally a fuse is supposed to have a nominal current of 75% its rating (22.5A for a 30A fuse), it will be happy to go higher than that momentarily, up to 30A at which point it should blow.
Of course, the point where it blows (how much current, and how long the current was sustained) varies with the type of fuse, and ambient temperature:
http://www.rfcafe.com/references/ele...ate_rfcafe.gif
With regard to your car, I am guessing you have some accessories or a short somewhere that is making it draw > 22A for sustained periods, making the fuse get warm, but not blow.
As for the resistance/corrosion, its true that it produces heat, that is how fuses function, they blow when the heat is high enough to melt the conductor inside the fuse, and the fuse only becomes hot when the current drawn through causes it to be a bottleneck/current limiting resistor. However, looking elsewhere for the corrosion/resistance is pointless, the heat is @ the point of resistance, corrosion on a wire down the path is not going to make the fuse hot unless it's causing a short.
Measure the current draw, get a multimeter or ammeter, it's pretty simple. Perhaps you have an aftermarket stereo pulling through this fuse?
Of course, the point where it blows (how much current, and how long the current was sustained) varies with the type of fuse, and ambient temperature:
http://www.rfcafe.com/references/ele...ate_rfcafe.gif
With regard to your car, I am guessing you have some accessories or a short somewhere that is making it draw > 22A for sustained periods, making the fuse get warm, but not blow.
As for the resistance/corrosion, its true that it produces heat, that is how fuses function, they blow when the heat is high enough to melt the conductor inside the fuse, and the fuse only becomes hot when the current drawn through causes it to be a bottleneck/current limiting resistor. However, looking elsewhere for the corrosion/resistance is pointless, the heat is @ the point of resistance, corrosion on a wire down the path is not going to make the fuse hot unless it's causing a short.
Measure the current draw, get a multimeter or ammeter, it's pretty simple. Perhaps you have an aftermarket stereo pulling through this fuse?
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