Single Switch Kit Relay Help?
 

So i am helping a friend wire up some lights for his truck and i know that the relay needs the 2 positive wires but i dont know what the small wires clamps to. The kit came with some small clam wire attachments but where do i connect it in with the relay?:thinking:
Thanks
and diagrams and pictures always help me

The best practice is to let the switch control the ground wire instead of the hot wires. Worst case if you have the long run of the ground wire for controling the relay should become shorted the lights will turn. If you have a long run of a hot wire for that purpose and it shorts out then if you are lucky the fuse pops or else the wires get hot and melts the insulation and maybe even worse a fire. There should be a picture on the relay showing how it should be hooked up. By picture I mean a little diagram of how it works.
If you need more info on wiring a relay do a search on Bing for relay wiring and it will show you all kinds of articles and examples for doing that.

The "clam thingy" is only to help make splices. You do not have to use them if you already have everything wired up.

Borrowed from another post..

I'm not trying to start an internet fight here... but I cannot agree with switching the ground. That is what a fuse is for... you'll have to fuse the positive on the switch, as well as on the load (to the relay, lights, etc.) If you use the proper size fuse (very small for switch, of course) it will catch before anything bad happens (such as melts insulation and catches fire).

See the diagram above, it does a fair job... just add a fuse between power source and switch (in the picture, its run off the fuse box)

I guess I waisted my time getting my electrical training in College, and from the automobile manufacturers, I should just have looked on here.
Of course you want to use a fues on the hot side of the circuit and that fuse should be the smallest fuse the circuit surge current will allow. Still best practice to use a switch on the ground side of the circuit and that is how they are wired from the factory.

WOW, temper, temper.
Since the switch should be used, and is being used to control the relay coil, and that coil will most likely draw miliamps, I would have to agree with eaglemikeo here. Should either the switch or the coil short, the circuit is protected by the fuse. I would also agree the wiring should support the fuse size for the control circuit, and the power circuit for the lights should also be protected by the proper size contacts in the relay, as well as the wiring be large enough to support the lamps as well as the fuse that is protecting that circuit.
As far as switching a ground I believe it to be bad practice just as switching a neutral in an AC circuit.
Of course I don't have all that college, nor do I have any auto manufactures training, but it is still my opinion, and it is set in my mind by 24 years military service working with electricity and electronics, as well as being a troubleshooting and repair electrician with a very large printing company for the past 20 years.
But then again everyone has an opinion.
Are the factory switches really wired to switch the ground?

I did not state an opinion, I stated what I was trained to do. If you were in the military then you should know the difference. The last question you asked has convinced me that I will not answer another question from another poster on here this forum pertaining to anything electrical and maybe not anything. If what you say is doubted and considered to be an opinion then there is no point in saying anything.
I looked on here to offer advice based on training received in various schools including the military, since the early 70s to the present day. Post what you want I won't be seeing it.

lol.
Officer: Why did you turn on your 150 watt lights, blinding the oncoming driver and causing him to crash?
Driver: But Officer, I was just following best practices

:wink:

Of course on the other hand if the lights were regular driving lights I'd rather them turn on because of a short.

Seriously, are fuses so unreliable that they sometimes won't break on a short?

Guess I was.

Honestly, I was just trying to offer some advice. To be safest, I'd simply state to follow the instructions that came with the lights. If they are ground switched, do that. If they are power switched, do that. Either way, the switch will create a break in the circuit, turning whatever it is off and on. The key points were made though, and (so far) agreed by everyone who has posted... use a relay, and fuse each circuit (switch circuit and load circuit)