Beartracker

Very soon I hope to be wireing some fog lights for my Tacoma but I have a question on the best place to pick up a hot wire. I'm thinking the best place would be the hot cable in the fuse box that comes off the positive side battery cable. I can just run my power wire from the lights to that pole, then through the rubber gromlet in the firewall to the switch that will be on the console.There will be an inline fuse used also. I would rather use one of the open hot fuse slots in the box but I can't figure out how to feed a wire to it correctly from under the fuse box to the fuse slot. The wireing leading in to the box is not long enough to allow me to raise it up. At least it doesn't look like it is. Running a wire in the box to the HOT cable is not a problem.
I don't want to hook it to the head lights or anything like that. It will be turned off and on from an independent switch.
Any other ideas? Mike

dibble9012

I would either buy an auxilary fuse box, or hook the wire directly to the positive post of the battery (make sure it is fused as close to the battery as possible). The reason for this is because the wire from the OEM fuse box to the battery is properly sized for OEM requirements, nothing else. You could probably get away with it, but I still think its safer just to go off the battery. Make sure you use a relay, dont put the switch on the actual power wire going to the lights.

Beartracker

The positive side of the battery was what I was talking about. There is a smaller cable that comes directly off the possitive cable of the battery and it powers the fuse box. I was just going to pick up my power off that post.I'm not going to hook up to my headlights or anything else. Do I still need to use a relay? If so where should I place it?. Thanks for your help and info. It's appreciated , Mike

dibble9012

The relay is needed even though you are not hooking them up to the headlights. The idea of a relay is to use the in-cab switch to send a small load to flip the relay, turning on the lights. It is safer than having high gauge/amp wiring going into your passenger compartment.

Now to set up a relay:

You will normally see 5 terminals on a relay. They are labeled 86, 87,87a, 85, and 30. Wire a small (18g) wire from an ignition hot source to your switch in the cab.(you could also wire it to the battery, but if you leave your lights on with the car off, you will kill your battery) Then take an 18g wire from the switch to relay pin 86. This wire is so small because it is only being used to flip the relay, not to power the lights.

If your relay has two 87 pins (87, 87a) then you can run a separate power wire to each lamp. Make sure you calculate your wire gauge correctly (i will give you a link at the bottom of this post). Connect your lamps to the 87 terminals.

Terminal 85 is ground, simply find a good ground or make your own.

Terminal 30 is fused power. This is the wire that would be coming off of your battery(constant power). Again, make sure you properly calculate wire gauge, and fuse sizes. Always fuse as close to the source of power as possible!

To calculate fuse size: watts/12 volts (example: (2) 55w fogs/12 volts=110/12=9.12 amps=10 amp fuse.

Take that information (10 amps) and go here to find your wire gauge. In this example, you would need 14g wire for a 10amp load.

I would mount the relay in the engine compartment, where it can be secured properly by a screw or zip-tie. Make sure it wont interfere with any belts/fans/etc.

Good luck!

Beartracker

Thanks for the info, that really helps. Mike

dibble9012

glad I could help!