I got a set of some small Hella fogs I'm going to use for aux. back-up lights and I want to wire them up relay method using an existing back-up line to trip it so that they come on without using an external switch.

Looking for best install ideas ie: relay location/12v access/trip wire tap to keep it simple and clean.

I have a trailer hook-up if that's of any benefit.

Thanks!

 

run a 14 gauge wire directly to the battery and connect it to the 30 post on the relay.
connect the reverse lights hot wire to the 87 post.
connect a the hot reverse wire from the trailer wiring to the 85 post.
connect the 86 post to ground.
ground the ground wires on the fog lights and cover the bolt in liquid electric tape so it won't rust.

after getting all the wires run you should coat the entire relay in liquid electric tape so water won't be a problem. i would mount it somewhere on the rear driver side of the frame.

don't forget an inline fuse close to the battery for the main power wire.

here are the ones i put on. but mine are on a toggle because i only need them when its pitch black behind me.

 

Lol, thanks, but I know how to wire relays.

I was asking as far as locating the relay under the hood and running the line to the rear or doing it all under the bed or any other ideas.

 

if you want the realy under the hood...why not put it in the "relay" box

 

Where would be the most convenient spot to pick up the existing back-up line to trigger it?

 

i would go from the fuse panel in the dash...then pull the wire thru on eof the grommets in the firewall.

 

The back up lights have their own circuit?

 

Give me a pic of how you would create this? Taking the fusebox out, removing the wiring, cutting the holes, then re-assembly is not worth it to me.

I just would put the relay on the firewall like I did here. This one is for my for lights. Convienent location. I now have 2 other circuit breakers right next to the relay now, so there is plenty of room.

 

Now you lost me ...

 

purple says its hard to put a relay in the relay box...hmmm

take the top off
separate the two pieces of the enclosure with the thumb tabs
pull the wire thru the relay location of your choice
connect relay
reassemble box

it took me longer to post the pics to photobucket and type this post than it did to actually do it... im not trying to be disrespectful...but that wasnt difficult.

relay box


top removed... blank locations



bug spray straw used for prop(didnt have a wire right off hand) pulled thru


relay box back together