Fog light switch wiring... first time with a multimeter...

[harrymaneuvers]

Ok so I am lost.

I got an auto-ranging multimeter so that I could wire my foglight switch for my JDM's...

"looking from the back of the switch:

1 3
--4
--5
2 6

#1- ground for the ON bulb.
#2- ground for the illumination bulb (this ground actually varies depending on the brightness of your dash)
#3- +12 volts when key is on ACC (powers both ON light and relay)
#4- +12 volts for illumination bulb when dash is illuminated
#5- out to relay
#6- same as above (can be used for another relay)

btw, the bulbs are super easy to replace, just open the switch and buy similar 14V 2mm bulbs at radioshack or somewhere. i had to replace both of the ones on my switch.

4) so you have to connect the above stuff if you want your switch to work. what i did was i just tapped into the nearby cruise control for connections 2, 3, and 4. using a multimeter you should be able to find them. connect one end of the multimeter to exposed chasis, and probe with the other end till you find:
-a constant +12, this is #3
-a constant +12 with dash illuminated, this is #4
-dim your dash halfway and probe for a ~6V, this is #2

for #1, there is none on the cruise control which means you have to connect a cable from it to exposed chasis somewhere convinient for you.

the final connection is the wire from your relay to either #5 or #6 or both."



So I tried to probe the back of the cruise control wiring harness and I was confused as hell. I think I found the wire that changes as I dim the dash... but 4 of the other 5 seem to not read anything and the other one jumps all over the place.


Can someone help me out here and just let me know what wires you wired your illumination wire and selector light wire to on the cruise control?

[chuckthefuk]

If your looking for a Illumination wire to have the dim features you can just tap into the cluster or the radio harness.

[harrymaneuvers]

um... right.


But how do I know which wire out of the cluster or radio is for illumination? Use a multimeter?

That is where I am at right now with the cruise control button...

[chuckthefuk]

Do you not a copy of the factory service manual for your year? The entire wiring schematic for the interior/exterior is in the FSM under WIRING detailed with labels.

Check the literature section.

-Chuck

[harrymaneuvers]

I have that but I am not the best at reading wiring diagrams... otherwise I would just look up the diagram for the cruise switch.

I will check it out though.

[harrymaneuvers]

So when I look at the diagram...

It looks like 4 and 2 are for the illumination bulb... does it matter which one I tap?

Also, 1 and 6 look like they are for the selector bulb... 6 gets grounded so that means I need to tap into 1?


I am looking at wiring diagram section 6-3 subsection K.

[harrymaneuvers]

Bump because I would like to get this done today...

I just need the two questions above answered by someone who knows wiring...

I feel like I already know but I would like to make certain so that I dont end up cutting and splicing back together wires that werent needed.

[harrymaneuvers]

You are the man!


So I tried to just hook up the one wire from the switch that goes to the relay... but something about only having one wire coming out of the switch that is supposed to turn on/off the lights didnt seem right... I felt like the switch needs to be grounded for the switch to work...


Either way... I hooked up the one wire from the switch to the relay and the projectors didnt turn on...


Do I really need to hook up the other four wires (two hot and two ground for the illumination bulb and the selector bulb) in order to get the switch to turn on my projectors?

[loganmossmusic]

I just did this last week. To start off, are you putting in a switch and relay that your car didnt have before? If you are, then I can help, this is exactly what I just did.
To power the relay, you need power coming from somewhere to the switch when the key is turned on or pin3 as you put it.
That power travels through the switch when you push it in and activate it. The pin it comes out of is pin 5 which needs to run to the relay. The switch does not have to be grounded for the relay to function, but you need to ground the relay. I do not know what relay you are using but this picture should help you to understand the system for powering the lights. http://www.classictruckshop.com/clubs/e ... oglite.jpg (http://www.classictruckshop.com/clubs/earlyburbs/projects/bosch/foglite.jpg)

Also, for the lights in the switch, just grab some jumpers and use a battery to test the wires by connecting positive to one and ground to another to find out which ones light up which bulb.

[harrymaneuvers]

Ok cool... So what I was trying to figure out was if four of the five wires are for the illumination of the two bulbs... how does the one wire left (that goes to the relay) complete the circuit for the fog lights?!?!


It seems odd to me that only one wire from the switch itself is going to turn on the fogs... you know what I mean?

Like if that wire is the hot wire... then which wire completes the circuit?

[chuckthefuk]

The relay itself has the positive and negative connections to power the fogs. The signal wire from the switch is sent to the relay. A relay is just a electronic switch that will go to the open/closed when it is fed the switching signal.

[harrymaneuvers]

So where is the power coming into the switch?

I thought the only two hot lines coming into the switch were for the two small lights in the switch itself...???

[chuckthefuk]

Check Page 84 (Fogs without DRL)

Connector (i7) which is the fog switch.

1 = 12volts (Black Yellow)
6 = Dimmer (Yellow)
3 = Relay Feed (White)
2 = Illumination (Yellow)
4 = Illumination (White Yellow )

The switch should have a 12v feed and a relay feed. I think the way your reading your initial prob of the switch is wonkey.

If your pulling your hair out just wire the switch up to a simple 12v light tester and experiment with the pins .
-Chuck

[harrymaneuvers]

OK so that got me half way there... I have my white fog wire connected to the relay and now I just need to make sure that I have the other wire connected to the right 12v power in line... I have my Black/Yellow wire (other wire) from the switch plugged into the blue (???) wire of the cruise switch... is that the correct 12v in????


I feel like I am so close!!!!




What would be really helpful is if you could give me the pin breakdown like the last post but for the cruise switch now.


Thank you again Chuck, your advise is invaluable.

[chuckthefuk]

Yes (L) stands for Blue and the blue wire goes to the fuse box

Pg 48 (i19)

3 = 12v (Blue)
5 = Cruise Control Module Feed (Orange Blue)
1 = Stop & Start / Clutch Switch & Cruise Control Module Feed (Yellow White)
6 = Ground
4 = Illumination (White Green)
2 = Illumination (Yellow Blue)

[harrymaneuvers]

Hmm... so if I have the white wire from the switch hooked up to the relay... and the black yellow wire from the switch tapped into the blue wire of the cruise control, the lights should work?

Again , I have hooked up the lights directly to the fused power source (wire to the battery with inline fuse) and the lights work perfectly fine...

[chuckthefuk]

That sounds correct as long as the two illumination wires are connected properly.

[harrymaneuvers]

oh wow... I cant just connect the two wires that are responsible for the switch function and skip the two switch lights for now?

G Damn it!!!


I think I realized that the scoobymods link and info I posted has the numbers on the switch wiring wrong... they were looking at it from the wrong side.


So I know where the black/yellow and the white wires go...

Can you tell me where the two yellow wires (and each of their numbers) and the yellow wire get wired too on the cruise switch? I think one of them gets grounded due to the cruise not having one.

[chuckthefuk]

You don't need to have these lights connected but it would make it more functional i guess

Pg 81. (i19)

4 = White Green
2 = Yellow BLue

And they tap into (i12) the "cluster or combination meter"

White Yellow & Yellow Blue

[harrymaneuvers]

well then crap!

I think my switch is bad...


If The lights should work with the white wire going to the relay and the black yellow going to the blue wire then we have a bigger problem!


AHHH!

Edit* so then white/green gets tapped into white/yellow on the cruise and yellow/blue gets tapped into yellow/blue on the cruise?

[chuckthefuk]

You are correct about the illumination wiring.

The relay should have nothing to do with the function of the switch.

[harrymaneuvers]

im 99.99% sure the relay is hooked up correctly...


I did a quick splice snap corrector thing to tap into the blue wire so my next step to make sure that it is connected is to ditch that for a quick connect terminal harness to tap into that specific wire.

[harrymaneuvers]

Eureka!


I have it working now!

All but the dimmable light but that will be worked out tomorrow...


My issue was the ground of the relay... It wasnt good enough... at all... I am surprised that I didnt catch it sooner.


Thanks for the help guys I appreciate it!

[geckoboy86]

harrymaneuvers, I'm going to be putting one of these switches in my car here soon to run some RS fogs. I have no wiring whatsoever for fogs in my Legacy. Think you can give me a detailed description of each wire (Color, Pin, What it does, Where does it go to)

Thanks in advance!

[geckoboy86]

Bump.

I have acquired a fog switch with harness. Its going to be operating my RS fogs. Its harness was only 5 wires.
I got my switch, has 5 wires.
Black
Black/Blue
White/Yellow
Yellow/Blue
Red/Blue

Anyone have an idea on which one does what?

[harrymaneuvers]

I am going to replace the gas warning light in the cluster today so I will break into this again and see where I left off.


Again, I just left it without the illumination or dimming feature... it operates the fog lights and the orange light comes on when the switch is pressed but that is it currently.

[geckoboy86]

That's how I'll take mine for now. On/off and active light. I'll worry about the rest later on. What pin needs to go where?

[harrymaneuvers]

Ok so here is what you need to do just to get the switch to work.

THe blue/yellow wire coming out of the back of the plug is the trigger wire that goes to your relay.

The black/yellow wire coming out of the back of the fog light plug gets tapped into the solid blue (with occasional white dots?) wire coming out the back of the cruise control switch.