Power source question

**Selride** · 02-09-2008, 07:39 AM

I've tried searching around, still not sure.. I have aftermarket fog lights that are taking their power straight from the battery. There's a switch to them that is ran through the firewall and into the cab. Sometimes i'll forget to switch them off.... bam, dead battery...

Is there a power-source under the hood that will give out good juice, and will only be hot when the ignition is on? I'd rather not try and mod the switch, but just want to re-run the power to something other than the battery.

Thanks!

**Mike's TA** · 02-11-2008, 10:01 AM

The connections for the factory fog lights?

**Selride** · 02-11-2008, 10:55 AM

These are 50$ autozone specials, technically "driving lights". I have them mounted behind a billet grille. There is a power going to my battery, then a hard-wired switch that runs through my firewall into the car.

I thought about getting some kind of relay that will splice into the power. Then run the trigger wire to a fuse under the hood that's only hot when the ignition is on.

**bigrondownhiller** · 02-11-2008, 01:16 PM

Originally Posted by Selride

These are 50$ autozone specials, technically "driving lights". I have them mounted behind a billet grille. There is a power going to my battery, then a hard-wired switch that runs through my firewall into the car.

I thought about getting some kind of relay that will splice into the power. Then run the trigger wire to a fuse under the hood that's only hot when the ignition is on.

You should definatly run a relay. The lights are probably pulling more current than the switch is rated for.

**Selride** · 02-11-2008, 02:50 PM

The lights came in an all in one box, switch, relay, lights, everything. I just want to connect the power to something that is only hot when the ignition is on.

I went to autozone today and explained what kind of relay I wanted: something inline on the power, that could receive a signal to flip on and off. Same analogy as the remote line to an amp to have it power on and off with the ignition. They said they don't even make such a thing

I just spent the last hour wiring the power to the Air Pump power in the fuse box under the hood. I have headers and had the air pump removed, so there's a 30amp current just begging to be used. I spliced into the Air Pump wire under the box with a 30amp inline fuse, which is perfect because the fog lights are rated at 30 amps.... wtf, the air line is hot all the time too......

**bigrondownhiller** · 02-11-2008, 03:00 PM

This is what you want http://store.classicgarage.com/hellarelay.html. Most auto parts stores have them near the fog lights or near where they have wiring products.

**Selride** · 03-10-2008, 04:24 PM

Update: purchased a relay from the local radioshak, can't remember the price, but it didn't break the bank.

Works like a charm, goodbye to dead batteries!!

I've included a short short write up for anyone looking to do something similar:

Inside the driver side fuse-box closest to the headlights there are 3 banks of 10-20amp fuses. Most of them are only hot when the ignition is on, but I would check with a voltmeter before splicing.

I chose the front most fuse because it was the easiest to get at when you pull the box up to get underneath. I used a inline splice to run my trigger wire back over to the battery side of the car.

You'll have to get the proper slide-on connectors at auto-zone, but connection to the relay is fairly straight forward. Connect the trigger wire, run the opposite side to a ground screw. Then run the "30" to your battery with an inline fuse, and it's opposite side to whatever you're trying to power.