Dash Heater Switches - Mk2 Dash - Mk1

Mk1 Dash Heater Switches - Mk2 Dash

Overview

The Mk1 and Mk2 heated window switches are technically differant in size and shape to each other. With the Mk2 connecters and switch being much larger. The back of the plugs looks similar but the internal wiring is totally differant. Both use a push non latching switch that utilises a relay to provide power to the widnscreen. Therefore most of the wiring can be similified down to a simple push to make switch and two LED/Bulbs to provide signiling to the dash. Most of teh hard work is done in the fuse box and you should not need to change this to get your new switches connected.

The internal wiring of the heated window switch from a 1995 reg car is shown below:

The internal wiring of the heated window switch from a Mk2 car registered later than 1987 is also shown below:

You can see from the two diagrams that the two swiches use differant pin positions although the interal electronics is very similar.

When you are purchasing your replacement Mk2 switches make sure that you also get a good length of wiring from the donour vehicle. The main reason for this is that the harness has some wires looped back to the switch . 5" should be pleanty to ensure you have theis cabling:

The basic wiring for the Mk2 plugs can be shown in the diagram below:

The Mk1 plugs is similar to this below:

The green led/light acts as a signal to show the main lights are on in the Mk2 switch. The Amber led/light a working light signal much the same as the Mk1 that shows when the heater is on. The Mk1 also had a blue light to show that the lights where on although as can be seen above does not share any similariry in its pin assinment and wiring.

Ford is notorious for changing its colour coding from vehicle to vehicle with the information above you should be able to work out which wire goes where if you follow the following examples.

Heated Front Windscreen

Mk1 Wires -> Mk2 Wires

White -> Brown/White 2 Black -> Black Purple/Blue -> Purple/Yellow Purple/White -> White/Blue Black -> Black

Basically that's how it's wired, there are 3 black wires coming out of the Mk1 for the windscreen heater, and 3 on the otherside for the rear window heater. Join them ALL together, but you have got to have ALL black wires joined together.

On the back of the Mk2 front/rear switch, you have 2 black wires running from each switch. Join them ALL together,

You should end up with 6 black wires on the Mk1 joined together, and 4 on the Mk2 switch joined together. Also remember that you have to have car running for the windscreen heater switch to work and light up orange. Also if you turn the lights on, the lights on the switch should light up.

Rear Window

Mk1 Wires -> Mk2 Wires

Blue/White -> Purple/White Brown/White -> Purple/Blue Purple/Yellow -> White Black -> Black 2 Black -> Black

This worked for me, but I'm not responsible for anything if you want to try it...

Submitted by FULLAFFECT Modified by: Max2thous10