Wiring in a link

[TRD_ZERO]

Im in the process of wiring in my g3 link. This is all new to me but after looking at a few threads i see people are wiring in a relay.
What is this for? Is it not as simple as matching the wires from my current loom to wire in the link plug and thats it? Ive got the computer pinout for my car and the link pinout, ive also got the details of where which wires go where from my loom to the link plug so i can do that stuff myself. Just wondering why people are wiring in a relay? All help appreciated. Sorry for the newbie question.

[l1ttle_d3vil]

i don't know the technical side of relays, but they're basically for anything that draws a heavy current (radiator fan, fuel pump, ecu etc). saves the contacts in a switch, or provides a decent current for whatever you're wiring up (i think)

they're pretty easy to wire in. what engine are you wiring up?

[TRD_ZERO]

Yeah probably should have mentioned that its a 20v blacktop in my ae111 levin.

[Stu-]

Some outputs from the link are ground triggers rather than power triggers and need a relay to change these around.

If you get stuck, send me a PM.

[mjrstar]

links are notorious for having a very poor earth switching capability for the fuel pumps, a few of us on here have had issues, so adding an extra relay to the +ve meant that the pumps would turn off when they should.

as mentioned earlier in other posts just about all triggers for the link are earth switched which means you need constant fused +ve to the relays you wire up.

[cogent]

I used a relay for the fuel pump in my AW11. Relays are like a switch that closes another switch - so you need to complete one circuit to complete the other.

You have 4 pins on the relay.

One goes to +12v, the matching pin for this side of the relay goes to the fuel pump wire on the link (or ground). This is the switching side.

Then the third and fourth pin sit in line with the +12v line on the fuel pump (or ground line if you wish to do it that way). This is the circuit that is affected by the switching side.

The link turns on, grounds the fuel pump output, which closes the circuit on the relay. Because that circuit closes, the relay automatically closes the other circuit and supplies 12v to the fuel pump.

I'm no electrical expert so I may have described that wrong/badly - but that is my understanding of how they work.

[TRD_ZERO]

Thats awesome info thanks ill give it a go and if i get stuck again (which i probably will ill ask more questions.

[cogent]

If you get stuck, Link have a wiring diagram on their site you can follow:
http://www.linkecu.com/support/dlandswu ... lation/G03

I might be wrong, but I believe the relay has an electromagnet inside it on one circuit, and a switch on the other circuit. So when you apply power through the magnet it pulls the switch gate closed - looking at the diagram you can see that

[thegreatestben]

a relay is good for switching a large current with a very small current.
Stops your switches from pooing themselves.

It is indeed an electromagnet, when the small current is applied, it creates a magnetic field which either opens or closes the other side of the relay depending on the type.