Skip the auto shop - Our mechanics make house calls

Q: Driver side headlights are dim. When I flash brights, the engine dies.

asked by on

So the driver side headlights are working but they are very dim. The passenger side are nice and bright. I replaced the alternator with a new 145amp. It came with a 105amp reman. Before I replaced the alternator if I turned the brights on or just flashed them the engine would die. Now after replacing the alternator I can turn the brights on and leave them but if I pull the lever back to just flash them real quick the engine dies. Any thoughts on where to look or what could be the culprit?

My car has 162000 miles.
My car has an automatic transmission.

A: Hi and thanks for contacting YourMechanic. ...

Hi and thanks for contacting YourMechanic. First check the battery cables for a clean and corrosion free contact. If the battery is good, then there is a problem with the wiring in the steering column. There is a short crossing the lights system and the dimmer switch to the ignition power wire. Check the wires on the dimmer switch to see if there is a loose connection and if there is a burned wire. If the wires are good, then check the light switch for any burned wires and see if the wires are loose. If there is no issues with those wires, then follow the wires to the lights and see if there is a loose ground wire on the frame or fender. If you need further assistance troubleshooting your vehicle, then seek out a technician, such as one from YourMechanic, that can assist you with the headlights issue causing the engine to shut off.

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!

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: Are High and Low Beams Separate Bulbs?

This is a great question since depending on the vehicle and manufacturer the lights can be configured in different ways. This can be a concern if you find your headlights are not working, since you need to know what type...

Q: A/C fan blows, but no cold air

Hello. Unfortunately there is not a switch for the seasons on this vehicle. If it is not blowing cold then it is usually an issue with low refrigerant. The system gets low due to a leak and the compressor will...

Q: Pulsating brakes.

Hello. All of the things that you listed could potentially cause the pedal to pulsate. If a wheel hub was recently replaced then I would move on to looking at the other hubs, as well as the rotors and pads....

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 Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...