RELAYS RELAYS what where and how

[EliteConcept]

i have a problem i seem to have a habit of fogetting to turn of my fog lamps.
What i want to do is wire the fog lamps so they can only come on when the parking lamps are on.

Where can i get a relay to do this at?
Is the installation pretty self explanitory?
How much do they run $?
i have 2 55 watt explorer pro comps what size relay should i pick up?


thanks
ryan

 

[Alec]

All you need to do is get switch power from the parking lamp circuit instead of a direct 12V. You don't need any extra relays or wiring.

 

[EliteConcept]

so just tap into the power wire in the parking lamps?
won't that draw to much power from the parking lamps and blow the fuse?

i foudn this wouldn't this work the same
http://www.radioshack.com/product.a..._name=CTLG_010_008_007_000&product_id=275-226
i'd just hate to have headaches with fuse blowings

 

[Alec]

Not if you just tap power for the switch and the lights themselves still have direct 12V power.

That ShadioRack relay is overkill.

You should have at least 2 wires going to your switch: power and signal. Right now that power wire probably comes from the battery, run with the power for the lights. Just tap the parking lamp fuse for switch power instead of that direct line.

 

[EliteConcept]

ok i think i see what your saying.
just in case i get extreamely frustrated the radioshack one would work though right even though its overkill?

 

[Hokie]

I agree with Alec, but I'm curious how your setup is wired now... Does your switch in the truck interrupt a relay circuit or the power/ground for the lights themselves. I've heard of people just having the switch break the circuit for the lights without using a relay, if this is the case, you will blow fuses if you have your lights wired this way and tap off of the fusepanel.

I always use relays b/c I trust them more.. and if you're lights came with the wiring harness, just connect terminal 85 (on the relay) to the parking light wire, and terminal 86 to ground. This would allow the lights to come on only when the head lights are on (and cut off when the head lights cut off)

 

[EliteConcept]

i have power from the batter to a switch and from the switch they run to the lights which are grounded independently.

with a relay wouldn't i have to run power from a 12v constant and from the parking lamps....?

 

[Alec]

Ohhhh, if you don't have a relay at all now you need one. Running high powered accessories without a relay is asking for trouble.

Easiest thing to do is to go get a light wiring kit from Autozone. You probably won't use all of it, but the important thing is they come with harnesses wires and a relay. In a nutshell:

Direct 12V power through a fuse to the relay.
Power to switch from parking light fuse.
Signal wire from switch to relay.
Ground from switch (on most switches).
Power from relay to lights.
Lights grounded.

So basically you'd be putting the relay in place of your switch now and running a new signal circuit through the switch. And yes, those kits come with instructions

 

[EliteConcept]

oh that sounds complex as a mo fo!

how would i tap the parking lamp fuse for power?

 

[Alec]

It's not. Basically adding 3 more wires than you have now.

 

[EliteConcept]

let me just see if i got this....i know you wrote it but let me just see if i understand.

1. power from battery or wherever to relay
2. tap the parking lamp fuse for power and put it on one side of my switch.
3. from the other side of my switch take that and run it to the relay.
4. run wire from relay to lights

 

[Alec]

Pretty much.

 

[EliteConcept]

not sure if you saw it but how do i get power from the parking lamp fuse ?

 

[Alec]

Figure out which fuse it is and take it out. Then take a wire with a stripped end and stuff it straight into one of the spade terminals. Then put the fuse back in wedging the wire in there. If you do it properly it is safe and reliable. If you do it wrong though....well don't do it wrong

And people please don't flame me for suggesting that way of tapping a fuse. It's worked for me on many different vehicles for many years. Much more reliable than fuse tapping kits and the like.

 

[EliteConcept]

hmm i see is there a reason you do it from the fuse and not from the wire near the parking lamp?
the relay wiring kit you suggested from autozone
i'd hate to buy that and not use the parts i have many parts in my garage i can use. I just need the relay
the radioCrap relay will work the same way?
heres its specs
Dead Link Removed

 

[Alec]

If it just has one power in, ground, and 2 outs then it will not work. You need one with that and a signal input; or one with the power ground and input, but only one output that you can split to the lights.

 

[EliteConcept]

ok good thing i asked
i maybe have to check out autozone then
did you see my question about getting the power from the fuse and not from near the parking lamp?

 

[Alec]

Originally posted by Alec
Figure out which fuse it is and take it out. Then take a wire with a stripped end and stuff it straight into one of the spade terminals. Then put the fuse back in wedging the wire in there. If you do it properly it is safe and reliable. If you do it wrong though....well don't do it wrong

And people please don't flame me for suggesting that way of tapping a fuse. It's worked for me on many different vehicles for many years. Much more reliable than fuse tapping kits and the like.

 

[EliteConcept]

i understand that but
i what if i just ran a peice of wire from the parking lamps to the switch ...would it work the same way?
i ask because i have side markers that i don't have hooked up anymore already connected to the parking lamp power wire so it'd just have to be ran inside the cab.
i must be off though i appreciate your help Alec!!

 

[Alec]

Ah, you asked your question backwards

Yes, that would work perfectly.