451 Add A Button

Mod Description

The button bank below the stereo is quite cool but what if you wanted to used one of the unused button spaces. Could it be done so it looks standard? Of course it can.

Mod Details

PremiumNo Difficulty Mod ID123 CreditEvilution For Linkhttps://evilution.co.uk/mod/451-add-a-button.htm Copy to Clipboard

Have you ever looked at all the unused buttons on the 451 lower dashboard and thought that you’d like to use them for something? Fog light switch, boot opening switch etc? Well, it can be done without buying new switches.

Using just a flat blade screwdriver and a file you can convert the blanks into functioning switches.

Pick A Button, Any Button

As you can see, I have quite a few spaces to choose from.

You may have a few more populated buttons. Obviously choose one that is empty.

Make The Button Work

First you need to remove the button bank and open it up.

This can be found here.

You don’t have to remove the button you want to use but it does make it easier. Insert a thin blade screwdriver in the side of the button, lever the clip in and push the button out.

There are 4 protruding tabs, file these down so they are flat.

Just like that (Tommy Cooper).

Reinsert the button and reassemble the button bank. Test the button works.

Of course it does.

If you don’t fancy taking the button out, you can cut the tabs out in-situ. Careful of your fingers.

Wiring The Button

You have 2 options here depending on what you are wiring. Negative switching and positive switching.

All of the standard items on the car (fog lights, boot release solenoid, etc) are negative switched. This is where a live wire is temporarily grounded causing a transistor inside the SAM unit to latch or switch on something else.

Most other things that you may add to the car that you want to switch (garage door opener, under car lighting, radar jammer, numberplate hiding mechanism, etc) will be positively switched. In these cases you will need to modify the controller of whatever you are adding in order to remove or bypass the physical switch. If the item’s controller also needs a latched power instead of a momentary voltage, you will need a momentary to latching circuit.

Negative Switching

Shown below are the 4 possible buttons you can use.

From the factory, the following buttons have these functions.

Button 1 = Front fog lights
Button 2 = Rear fog light
Button 3 = Alarm disable
Button 4 =  TPMS reset

The number above relates the this wiring diagram.

The pin marked with a brown square is the earth, this is already present.
The pin marked with a red square is where you should fit your wired terminal.

If you look at the button bank, you can just see through the connection to the PCB below, in the bottom left corner you will see a number 1 which relates to pin number 1.

The pins are counted from 1 (bottom left) to 9 (bottom right), 10 (top left) to 18 (top right).

The heated seat buttons use transistors on board so these are not ideal for using as a standard switch. Stick with switches shown above which are straight through momentary action switches. You will need to add a wire to the connector to use it, These just push in.

They are MQS terminals.

Examples

Boot release switch
Fog light switch