Skip the auto shop - Our mechanics make house calls

Q: Electrical issues. Brake lights won't go on. Replaced fuse but still keeps blowing.

asked by on

My brake lights weren't working, so I replaced the fuse but it kept blowing. All of a sudden, all the power to my dash died and some times when the stars are aligned it will work. I'm trying to get it running agin since it is my only ride. Would it be a relay?
My car has an automatic transmission.

Hi, thanks for writing in. Whenever a fuse continually blows, you have a short that needs to be located. You stated the power on your dash died and followed with your still trying to get it running. With this I will assume the truck is not running and the dash lights are part of that problem. When all the power to a vehicle disappears, this is usually a product of wiring branching directly from the battery. There isn’t one relay that powers everything on your vehicle. Relays can’t handle that much current.

A test light is the best tool to locate such electrical problems. If my assumption is correct and you have lost power to everything, you will need a wiring diagram and a test light and begin testing near the battery. If some systems are still working, I would trouble shoot where the short is to the brake lights. Do this by studying an electrical diagram to locate all that that fuse powers. Then one at a time, disconnect the suspected components until the fuse stops blowing. It is very useful to use a circuit breaker when doing this. That way you won’t need to replace the fuse after it blows each time.

If you still need help with this, I recommend the following inspection to help you out. [https://www.yourmechanic.com/services/electrical-components-are-not-working-inspection)

Good luck!

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!
  • Home
  • Questions
  • Electrical issues. Brake lights won't go on. Replaced fuse but still keeps blowing.

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: New IAC Valve - High Idling but old IAC Valve normal (800/900 rpms) 1993 Saab

Hello - I think you were on the right track with the idle air control valve. It sounds like your engine is getting extra air from an intake leak somewhere. It's also possible there is a throttle body problem. The...

Q: Dies when you step on throttle

The throttle position sensor (TPS) or manifold absolute pressure (MAP) sensor may not be passing the correct signals to the computer in order to give the correct amount of fuel to the engine when you accelerate. You can disconnect the...

Q: Brake light does not work.

Use the power wire from the brake light switch to activate the rear brake lights. By having an alternate power supply, ;the brake lights have no control without a switch, so the module is on but not functioning for the...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...