Relay Questions

[snocross1985]

I have heard a lot of people using relays on their fog lights. What does a relay do? Do i need one if I am wiring just 2 55 Watt fog lights that will run off their own switch?

 

[Nate1]

A relay acts like a high current switch.
When you supply 12v through a certain pin, it closes (or opens depending on your application) the switch and allows roughly 30 amps to flow. You can buy even higher amperage relays than that, but its not necessary with fog lights.
Think of a relay as an industrial strength switch, although it is slightly more complicated to wire up.... but not bad.
-----Nate

 

[udmsvt]

if they use their own switch and power supply, you do not need a relay. i have on mine a relay wich basically takes the 12v signal from when my parking lights are on and uses that to effectively "switch" on my fogs which have their own power lines. think of it this way: wither you can go get the mail, or you can ask someone else to. either way, it gets done...but the other person wont do it on their own.

 

[snocross1985]

OK udmsvt, thanks for everything again Lately you seem to be giving me some of the best answers for my problems and i appreciate it. I heard you were doing a body lift on your Ex, how'd that go? heard you were having trouble.

 

[udmsvt]

i love to help. yes, i am doing a body lift and its still not done...almost 3 weeks in the making (lotsa troubles!) my thread on it is here

 

[taxx]

Originally posted by udmsvt
if they use their own switch and power supply, you do not need a relay.

I disagree. Without a relay you need a heavy switch and some heavy wiring goingall around with a relay you have less distance on the heavy wiring from the battery and fuse. This allows you to use any switcha nd run small wires to the interior then large wiring (fused) from the battery to the relay eliminating the need for lots of heavy wiring.

The more heavy wire you run thee thicker it needs to be to account for resistance. 2 55watt lamps aren't bad but why not do it right the first time and be ready to go with bigger bulbs later? Or eliminate the risk of meling a switch or wiring? I learned the hard way years abo melting wires behind the dash. it can be dangerous.

 

[udmsvt]

i have a tendency to run many many wires. let me rephrase my previous statement:

you dont necesarily need a relay, but it is a good idea to have one in place.

 

[taxx]

lol. It is all where you put the emphasis I guess like "you don't NEED a relay"