Handbrake Warning Light

The Ford Mondeo hit our roads in 1993, and has consistently been a sales success. Now on its 4th incarnation, it remains a drivers favourite.
For more information, visit the Ford Mondeo forum on TalkFord.com, the definitive resource site covering all Fords from the present day to the 1970's.

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Overview Guide
Ford Model:	Mondeo
Petrol/Diesel:	Both
Estimated Cost:	£0-5
Difficulty?	Easy
How long does this take?	1-2hrs

Background

If the Handbrake Warning Light fails to illuminate when the handbrake is engaged, it is going to be one of three things:

1. The bulb in the dash has died;

2. There is some dirt in the handbrake switch itself on the electrical contacts or the switch has a mechanical fault and is staying open-circuit;

3. The electrical connector and multi-plug on the brake fluid reservoir low-fluid switch have become contaminated and gone high-resistance.

Method

In the case of the bulb in the dash having died, you will have to remove the instrument cluster and access the bulbs. The bulb holders twist out and then you need to pull out the wedge-type bulb and renew it. Test it with a multi-meter (for continuity) or swap for another bulb to check it really has gone.

If the switch has failed, it should be easy enough to fix, although you may need some compressed air or silicone switch cleaner spray. For good access remove the centre console.

The switch itself is activated by the handbrake lever pushing or releasing a plunger which makes or breaks an electrical contact. The circuit is completed by switching to ground. Remove the coin holder from the centre console near the handbrake lever.

Using a tin of compressed air and a nozzle (usually available from a photographic store such as Jessops), you should be able to blast any dirt off the switch by placing the nozzle in the hole where the coin holder was. Switch the engine on and with the foot-brake applied, engage and disengage the handbrake a few times.

If the light still refuses to come on, you may need to use some switch cleaning spray. This is preferable to WD40, which leaves a residue and should not really be used on electrical contacts. Make sure you open the car windows though - the spray is not particularly pleasant if you inhale it!

Lastly, if the multi-plug has poor electrical connections due to brake fluid ingress, clean the insides of the connectors with cotton buds and then use a very small file to reveal the bare metal once more. Both the low-fluid switch and handbrake switch route through this electrical connector, the third pin going to ground.

Other than a wiring loom fault these are the only things that can cause the bulb not to illuminate.