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Ford fog light switch wiring
davrus - 1/10/10 at 08:32 PM

Hi ya, i have a ford fog switch, poss a sierra. It is the one that puches in and the little light lights up in the middle of the button to tell you they are on.

Now my question is what wires go where

I have 4 terminals on it numbered 1,2,3,4 it also has a number 5 on it as well but no turminal coming out.

All help appreciated

[Edited on 1-10-10 by davrus]


daniel mason - 1/10/10 at 08:48 PM

i asked this very question yesterday and got no replys! so am also interested


snapper - 1/10/10 at 09:05 PM

Had huge problems with this recently, switch has 1234
Wiring diagram has 1245
So I used a battery and bulb to find power to fog light and power to indicator bulb.
If I get to the car tomorrow I will have a look


snapper - 1/10/10 at 09:28 PM

I think I have deciphered the Haynes manual
4 power from lights
5 power to fog lamp
2 power from dash illumination
1 earth


Madinventions - 1/10/10 at 10:38 PM

The wiring diagram in my Sierra Haynes manual gives the following:

1 (GE/RT) This is the switched +12V output that goes to the fog lights themselves. No relays are used for this circuit so I assume the switch contacts are reasonably rated.

2 (GR/OE) +12V feed from ignition/battery

3 (BR) Ground

4 (GR/OE) This is the supply to the internal bulb used for illumination and is fed from the 'illumination potentimeter' (the one that controls the brightness of the dashboard illumination). This bulb can be on regardless of whether the switch is pressed or not.
Note that the bulb between pins 3 and 4 is not the LED in the middle of the switch!

When the switch is pressed, it should connect pin 1 to pin 2.
The LED is connected between pins 1 and 3 so it will automatically come on when there is +12V at pin 1, ie, the fogs are on.

Hope this helps,

Ed.

[Edited on 1/10/10 by Madinventions]


Madinventions - 1/10/10 at 10:56 PM

Here's a quick sketch that may help...

Fog light wiring
Fog light wiring


Ed.


davrus - 2/10/10 at 06:11 AM

Thats great Madinventions.

Will let you know how it goes.

Many thanks for your time and effort.

Dave


Madinventions - 2/10/10 at 03:27 PM

Hi Dave,

No problem, glad to help!

Ed.


mad-butcher - 3/10/10 at 08:04 AM

From memory doesn't the fog lamp have to work on headlamps only

tony

[Edited on 3/10/10 by mad-butcher]


Madinventions - 3/10/10 at 09:38 PM

Hi Tony,

Yes, I think you may be right there... The sketch was primarily to show how to connect the fog switch, but to be compliant you'd probably need to remove the 'turn on illumination' switch, and connect pins 1 & 4 to a source of +12V that is live only when the lights are on. With standard Ford wiring, pins 1 & 4 of the fog switch are fed from the +12V that lights up the dashboard which is only on when the lights are on.

Best regards,
Ed.

[Edited on 3/10/10 by Madinventions]


davrus - 5/10/10 at 11:51 PM

Interesting.
So what are your thoughts on this then.

I am using standard sierra stalks which means my headlamps are earth switched, now in order for the fog to work on main and dip i have to use the earth from my head light switch output to give power to my fog switch as i cant use any wires from my headlamp relay as flicking to main beam kills my dip beam which means no power to headlamp relay (hope that makes sence). Sowhat do you suggest??