Runner4

I have a set of Pilot Fog Lights that I have had installed for about a year. I installed them myself using a 12V 30 A relay, a Toyota OEM switch, and an inline fuse on the positive wire which is directly connected to the battery terminal. About a week ago, my fogs quit working and when I investigated why yesterday, I noticed the inline fuse was not only blown, but melted. What could have caused this all of a sudden. These fogs worked fine for over a year (I use them all the time), and I can't figure out why the fuse would have melted. Any ideas?

TRunner

I have a some what similar situation. Though mine might be because the wire to the lights rested against the pully for a short time and became exposed and grounded. The fuse and box are melted together a bit, but it still works. I haven't hooked it back up to my battery since the rebuild but I will try it again this weekend.

tombothetominator

yup, sounds like a grounded wire to me.

Runner4

I checked all the wires and they all look good.

Yoda

The fuse is melted due to heat (duh). The heat is caused by resistance in the fuse holder (rust? battery corrosion?). Replace the holder with a high quality one and good to go....make sure it is rated at least 30 amps, preferably more.

Flamedx4

Yep.
Grounded wire is a short - fuse snaps instantly. Melted fuse/wire/holder is because of high resistance generating heat - usually caused by corrosion or a lose connection.

Runner4

This sounds very logical. What would you consider a high quality holder?

Steveh29

Yep. I had the same thing happen with a set of KC lights. The inline fuse was in a rubberized holder but moisture still got inside. It corroded the terminals and by the time I noticed it the fuse holder and about a foot of the wire had become somewhat melted. I used a marine inline fuse that I got from a local boating supply store. Look under 'electrical' and then 'terminals and fuses' at this site. They've got a waterproof inline holder if there's no boating place nearby.

http://www.jamestowndistributors.com/index.asp

Koz

You need to replace the power line and fuse holder from the battery, a 30 amp fuse sounds a little high. Check the manufactures power (amp draw) requirements for those exact lights. You may want to use a larger gauge wire then it calls for. Make sure you route the wire as not to be in contact with any heat or where the insulation could be worn. The fuse should be as close to the battery as possible. You want to use dielectric compound/grease on the fuse contacts. After you have run the wire you want check the amp draw on this circuit to make sure the lights are within the normal range. You may want to put some compound on the bulb connections also; this will insure good contact and reduce heat.

Koz

trdslinger

I got a fuse holder and fuses from a boat place too. I got
this one.
I figured if it can install on a boat, then it's good enough for me and my truck.

Koz

Looks like a very good fuse holder, just mount as close as possible to the battery, still use the dielectric compound, and check the final amp draw. The reason for mounting the fuse close to the battery is; if the unprotected wire (NO FUSE) between the battery and fuse is shorted to ground you could possibly fry every wire and electrical component in the car, possibly totaling the car. I’ve seen it happen, it was ugly!

Koz