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・Save up to 30%

Get a quote

What others are asking

Q: Dim high beams; low beams only shine 60-70 feet

With this being a new 2016 Chevrolet Silverado 2500, if the mileage is still low enough to be under the manufacturer's warranty you may want to have the dealership look at it to make sure there is not an issue...

Q: Traction Light on

It sounds like there is a serious problem in the traction control system. Fault codes need to read out to see what the Electronic Brake Control Module (EBCM) sees. For the traction control system to work properly, it needs to...

Q: bogs down with heavy acceleration no codes all sensors read normal fuel pressure is ok.

This sounds like a very tricky problem to diagnose. Did you check the fuel pressure with the fuel pressure regulator disconnected? Perhaps there isn't enough fuel pressure at full throttle, or the fuel pressure regulator leaks and floods it out...

Related articles

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...
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...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.