Why Do Dashboard – Park Lights Come on When the Brake is Pressed & How to Fix It

To many people it is an utter mystery – just why do a car’s park or dashboard lights come on when the brake pedal is pressed? Some car owners pry their dashboards open looking for wiring faults, while others probe the entire car searching for electrical problems. But the problem is sometimes simpler than they may suppose.

The problem with the dashboard lights coming on when the brake is pressed can also be manifested in a similar problem, that of the parking lights turning off when the turn signals (left or right indicator) is activated. In many cases, the problem has the same source. Some of the things a car electrician will look at when troubleshooting these problems include checking for:

• Grounding faults
• Electrical Shorts and
• Faulty components such as switches.

The Most likely Cause of the Park Lights Coming On

The most likely cause of the park lights coming on, when the brake pedal is pressed, is a grounding fault. But not to worry, it may require only a very simple fix. The grounding fault could be caused by:

• Purchasing the wrong replacement brake lights – Some car owners make the mistake of replacing double contact brake lights with single contact lights. In simple terms, this will cause an electrical fault because single contact bulbs are missing a circuit.  If the vehicle came with double contact bulbs then they should be replaced with double contact bulbs, a single contact bulb won’t do.
• Corroded contacts – Rusty bulb contacts can cause the same problem. Check and clean all the park lights and brake light bulbs to ensure that they aren’t corroded. Before fitting everything back together, ensure that everything is working.

Try and seal any hole through which water can enter the lights and corrode the contact points. However, be careful not to seal the drainage holes at the bottom of the lights.

Troubleshooting Automobile Wiring Faults

Modern vehicles have complex electrical wiring that runs under carpeting and through the vehicle’s frame as well. Trying to actually pinpoint wiring faults can be a major undertaking that can take several hours or days, not to mention the inconvenience of pulling apart the vehicle’s interior.

Before one goes digging, it is best to check the simple things first. An important question to ask when trying to resolve a problem such as this is: what action may I have taken that could have caused the current problem. The answer to that question may just be the key to solving the problem.

For example, driving the vehicle in deep water could have caused a short, or some other electrical problem. Sometimes the consequences may not show up immediately, in the case where a vehicle was driven through deep water, rusting may affect the vehicle’s electrical system several days after the fact.

Don’t rule out tinkering with the electrical circuitry either. Car owners should try and recall any change that was made to the vehicle in recent times, whether by the owner or someone employed to do a job.

Fixing the Park Lights and Brake Pedal Problem

While the brake pedal and park light anomaly can sometimes be fixed by resolving circuit faults such as improper groundings or shorts. In many cases, the problem is simply one of using the wrong set of bulbs. If a car’s tachometer, dashboard or park lights come on while applying the brake, simply replace the brake light or check that their contacts are not rusted to resolve the problem.