rossmc

I've got my MOT tomorrow and I'm struggling to figure out how to wire up my rear fog switch. I'm not bothered about it lighting up the switch, just want it to switch the rear bulb on and off that I've put in.

I've wired up the rear bulb correctly to the point where I've fed the cable through to the front dash and can switch the light on and off manually by bridging the connections, I just can't figure out the switch wiring. I've tried a good few combinations of the wires but none will switch it on and off, it's either on or off and pressing the switch doesn't make any difference.

Here's a pic of the wires I'm trying to connect the switch to:



Heres the switch with the 5 wires coming out of the back:



There is red, green, purple and two blacks. If anyone knows which two wires to connect to get it working please let me know,

Any info would be great, really wanting to pass tomorrow, the car is a 95 WRX, the switch is out of a 98 classic

Thanks again,
Ross

WRX_Dazza

you will require a luminated switch to pass mot, if i remember correctly !!

WRX_Dazza

go buy a small illuminated switch (2 wires) and mount it on the lower console (right hand side) the switch automatically illluminates when active.

try it before you mount it (about a £5 from car shop)

Jaywalker

A switch is just a break in current so could you just use a multimeter on the continuity setting to find the switch wires????

or you could download a scooby manual and have a look at the wiriing diagram or if your rushed do what drx dazza said just to past Mot

Daz_01

Hi mate it definately needs to be illuminated to pass an MOT and also I would want to be running the fog lamps though a relay unless you want a potential bonfire.

Regards

supernovauk

If its genuine rear fog switch and you trying to wire to an import e-mail me and ill tell you what wires go where as i did mine yesterday,All you will need is 3 wires 1 to fog,1 to the power which you have and also an earth,post a pic of the front of yr switch so i can make sure its a geuine rear,

supernovauk

Also post a pic of back of switch so i tell you the right color wire to what as i cant make it out properly in yr pic,2 wires to light up fog sign green,2 wires light up switch orange and other is fog,

rossmc

Here's a pic of the switch. It's a proper impreza rear fog switch, I removed it from a car in the scrap yard myself.



The wires are purple, green, red and two black

rossmc

It's just a single low power led bulb, its not a set of high power front fogs, so am I right in thinking I won't need a relay? I'm stealing a feed from the rear light which is fused, so I'm thinking if anything went wrong with the fog bulb, the rear light fuse would blow?

rossmc

That's exactly what I thought, but I couldn't get it to break current, which was what was confusing me. I was only trying two wires at the same time though, but if it needs a thrid wire for the earth, that would explain why it wasn't showing up on the continuity test.

Yox

There still needs to be either, a light on the dash or the switch has to illuminated, when the fog light is in use to pass an MOT.

rossmc

Tell that to the tester who passed my car yesterday with a switch that doesn't have a light

supernovauk

You dont need a on and off light on your switch i have never had one until i fitted the original subaru switch the other day and it passed for 4 years.

supernovauk

I had to work this out myself as i couldnt find help anywhere on the net so hopefully this will help alot of people

Wire colours change on different rear fog switches for some reason so follow the pinouts instead

Pins are set as below

l l
l
l
l l

numbered as

1 2
3
4
5 6

Pin 3 goes the feed to the fog bulb
Pin 5 and Pin 2 goes to live power when you turn your lights on not ignition live.
Pin 6 and Pin 4 goes to earth

Just so you know

pins 2 and 4 are the + and - for the fog light sign so it lights up green
pins 5 and 6 are the + and - for the orange on and off indicator on the switch
pin 3 is for the fog bulb

If for some reason your switch doesnt light up it will probaly be the bulb in the side as i had to change mine

Good Luck !

Yox

I got this, bit ambiguous on the wording I guess.

"6. With dipped headlamps and the ignition switched on, operate the rear fog lamp switch and check that a rear fog lamp
. is fitted to the centre or offside of the vehicle

. is working, and

. does not flicker when tapped lightly by hand.

Check also that the drivers tell-tale works properly.

7. Check the presence, condition, security and operation of the switch."

scooby546

iTrader: (1)

^ +1, mine failed the MOT because the switch for the rear fog light didn't have a warning lamp to advise that it was turned on.

Also, if you're using a single LED then you're correct, shouldn't need a relay as its v low current (mine uses twin LEd arrays without a relay)

rossmc

That is absolutely perfect instructions! You are the first person on this forum to create a definitive guide, this should be a sticky in the tutorial section!