Wiring Relay for Fogs

[den0va]

Okay so I was using the DIY Guide on CompleteFTO and am slightly confused. Can anyone help me?

Is this right? Like does it really matter where the wires go like obviously 30 with 87 and 85 with 86, but is where my nunbers are, are they correct?

relay2.jpg (37.43 KiB) Viewed 406 times

What is positive and negatively charged?
30 and 86 are negative and 85 and 87 are positive?

[PHIL069]

You have the numbers correct.
Positive feed to switch can share an Acc 12V fused circuit already in cabin
85 = Positive wire from switch
86 = Earth to complete switch circuit
30 = Positive feed direct from battery via its own fuse
87 = Positive sent direct to lights

BTW you can get relays with 2* #87 pins, one for each light.

[den0va]

Ahh okay cheers Phil I was having a look at it before and kinda get the concept of what needs to be done. Like the two wires in the middle of the plug for the switch are 0v but when the switch is pressed in, they read 12v. So the outcome you want is to wire the relay in with those wires so when the switch is in the on position will read 12v which then goes to the relay, and on the relay the wires for the foglights are powered by those 12v. So what is really happening is that the fogs aren't running through the switch directly, so it won't burn out; and is running from the relay. Is this correct? BTW you don't happen to know which wires are pos and neg? I already know the red thicker wires are fogs, the wires on the other side are parkers and the middle ones are power.

[PHIL069]

Yes, the relay is a switch with 2 seperate circuits, a switching circuit and a circuit from battery to lights (load circuit). When you switch the fog lights in the dash the low current draw 12V is directed through the 85/86 circuit and that closes (turns on) the 30/87 circuit which allows the high current draw 12V to go from the Battery to the lights. This stops the lights' current draw going through the dash switch and allows a thicker wire to go from battery to lights.
The wire colours I'm not sure of as I haven't fixed mine yet.

Edit: So in that pic...I wouldn't connect the wire going to #30 from the switching wire, I would run a seperate fused wire direct from battery to #30, and install the relay under the bonnet.

[PHIL069]

Moar like this....

[den0va]

Seems like more work than I thought in the diy they explain it differently. http://www.completefto.com.au/CompleteFTO.asp?aid=501 Is there a lazy way out lol? Like in this guide? I don't care where the relay is installed behind dash or under bonnet... What would be wrong with using the existing foglight fuses etc?

[den0va]

Couldn't it just be spliced at the existing 12v, this seems to make more sense to do it this way as it's easier lol

[PHIL069]

Sorry, you can do it that way.
I was describing wiring in a new circuit for the fogs, which is moar work. I am too used to wiring in new lights at work

[den0va]

Haha, I understand what you're getting at though; I just don't have the patience and time to make a whole new circuit and then wire it in under the bonnet. I just want a quick and permanent fix, although your way is safer and more professional. Nonetheless, I now understand what needs to be done. Thanks Phil

[PHIL069]

[shadowarrior]

BTW you can get relays with 2* #87 pins, one for each light.

Hey Phil, is this what you are talking about? I can see the centre pin is marked 87b and the others are 85, 86, 87 and 30. Need to put this relay for the fog switch as well.

[silverGPX]

More*

[shadowarrior]

More*

[PHIL069]

It depends on the circuit within that relay, being that the second 87 pin has a "b" could mean that you are switching from #87 pin to #87b pin ie. when you flick the switch to "on" #87 gets power through from #30, when you flick your switch to "off" #87b gets power through from #30. You could test this with a 12V globe or test light.
If you are wiring it the same as denOva then you only require one #87 pin, you can use that relay and just put a blank crimp terminal or electrical tape on #87b.

[shadowarrior]

okaye thanks. yeah I will be taking the easy way out as well following the DIY. now, need to get a multi-meter, a wire slicer and some clips!!

[den0va]

haha yay for the easy way out was supposed to do this today after work but I fell asleep :S

[shadowarrior]

haha yay for the easy way out was supposed to do this today after work but I fell asleep :S

lol post here when you get it done!

[payaya]

Whats the point of doing all this extra work?

Isn't it common sense to use the wiring already at the switch? The issue is not wiring related it's the current passing through the switch.

So permanent positive wire needs to be jumped before entering the switch. Connect this to 87 of the relay. Cut the switched power output of the switch and hook the harness side that up to 86. 85 to ground and 30 to the switched power output of the which goes to the lights.

So essentially the main positive is still live and connected to the switch, but because you are jumping the wire before the switch, the current is actually sucked up by the relay so no more melting switch.