Skip the auto shop - Our mechanics make house calls

Q: Really weird brake light activity

asked by on

Ok so I was working on a freinds car and she informs me that her brake lights don't work. So I got to inspecting it looking for the issue. Well her brake lights and running lights are the exact same bulb but with 2 coils. Both coils were in tact, there are no blown fuses and I figure the wiring is fine cause the running light coils still work in both lights. Now I know about the hole brake switch issue but here is the kicker, there is a third brake light on her tail fin and that one works like it should. So any suggestions

It is possible both bulbs are burned out. The higher wattage brake light filament in each bulb should be tested with an ohmmeter to make sure the filament is intact. The bulbs can also be powered off the car to see if both filaments work but be wary of short circuits if you try something like that. If the bulbs are good, check for corrosion and/or faulty connections in the bulb socket, wiring, and/or terminals. Finally, check for power at the bulb socket and check the circuit ground. If there is no battery voltage, obviously the circuit will have to be traced to find the fault. If there is voltage, check the ground. If you want these steps performed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a brake light bulb circuit diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Really weird brake light activity

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Brake pads need replacement at only 16,000 miles

Hi there. The brake wear indicator will illuminate when your brake pads are worn or there is a problem with the brake pad sensors. The brake pads may be worn enough at 16,000 miles to warrant replacement. I suggest you...

Q: Dash lights going in and out

I will assume the lights are completely turning on and off randomly. In this case, there is a possible loose connection behind the instrument cluster. Other vehicles of the same model with similar symptoms were affected by a faulted dimmer...

Q: Brake lights and blinkers don't function

Hello. Cool and rare car you have. I would suggest having a technician check the electrical components in your vehicle. Also, I recommend checking the fuses, brake pedal switch, and electrical wiring to the tail lights. I would suspect that...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...