fog light relay modders beware***
 

so ive had this mod for a long time and its been good... sorta.. not until recently the fog lights didnt turn on n i was trying to figure out why. i checked the fuse box and it was good.

when i went under my driver steering column i saw that the fog light relay area was burnt and one of the fork pins melted the plastic female section...

Just a warning to yall with this mod. check out your connectors to see if its still healthy.

ill post pics

*please note. as stated below. problem was due to higher gauge wires. Double check to be safe fellas! learn from me :) *

Attachment 245477

heres the picture...

It looks like a bad connection caused this. Using crimp connectors like those are the culprit. Over time they will cause high resistance because of bad connection. Solder the wires together and heat shrink them. Another cause is because the circuit is drawing too much heat.

Actually his problem is the wire thickness, it's not thick enough. Wire crimps are ok as long as they are assembled correctly with the right tools, but I agree it is a common source of problems because most people don't crimp them properly.

Look closely at the first pic and the copper wire is waaay too thin for the fogs. Looks like he's using a 18ga wire. This relay powers the fogs so on 55w halogens, it will pull about 110w total(so about 9 amps). Factor in some extra resistance for all the extra wiring long runs in the car, let's say worst case it pulls 11amps. 18 gauge wire of high quality and multi strand at best can carry about around 16amps or so, his looks like solid conductor wire of lower quality which has higher resistance, so it won't carry as much current. When you run wire to their limits, they will heat up no matter what. They can not dissipate the heat fast enough, and there is too much resistance at the limit. Even at 75% of the rated load, the wire will still slowly heat up. It may possibly still melt over long periods.

Anyways, long story short. Throw away the electrical engineering talk for a sec. Use some good quality wire of AT LEAST 14ga. It can carry 32A which is double the capacity of the 18ga wire. Best to use 12ga, but 14ga is acceptable. FYI: Lower number on the wire gauge scale means thicker wire, and higher number means thinner wire. Also, just because the plastic or rubber insluation on the outside of the wire is thick, doesn't mean the wire is actually that much better. What really matters most of the time is the thickness of the actual copper wire inside.

Ah yes. Gauge thickness does play a role.

your wiring gauge is not thick enough!

Jeff, I hope you used the correct wire when you did the fog mod to my car. :p

good catch jeff.

Looks like we're gonna need vinegar to clean that mess up.. =x speaking of fog light mod, I need to find time to do that ish!

hah naw i ended up just putting it back to stock. keeping it simple even though i like the whole fog light as my DRL.

but yea i wanted to post this up in case people (like myself) have accidently used thinner gauge wires when doing this.

Lookin out for yall 2GSrs.

Thanks for the info though!

gauge of the wire is definitely thin... but it is always best to do routine inspection on mods even it is working good.

good information as always! :thumbup:

Thanks for the heads up and great info Jeff