Skip the auto shop - Our mechanics make house calls

Q: Turning brights on causes the engine to die

asked by on

I just purchased this used Yukon and I was looking it over in my driveway. I had it idling with the hood up when I noticed the left headlight was really dim. My uncle told me to turn the brights on and when I did the vehicle just died. It dies every time you turn the brights on. Doesn't matter if you push the lever forward or back.

My car has 160000 miles.
My car has an automatic transmission.

Hi. This sounds like the the alternator is weak and is going bad. When you turn on the head lights, A/C system, or radio it puts a load on the alternator and the alternator should be able to handle this load if it is working properly. Your alternator seems not to be able to handle the load from putting on the high beams. If you need help with this repair, a certified professional from YourMechanic can come to your home or office to replace the alternator for 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!

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: Head lamp stays on

Hey there, thanks for writing in about your 2010 Mercedes-Benz R350. Have the control module under the driver's seat checked to see if any water was introduced and has gotten it wet. If it has, then the A/C drain hoses...

Q: Computer saying rear access is open when it's not

The contact switch could be bad, or the rear latch may need to be adjusted in order to allow the door to close completely. I recommend having a mechanic, such one from YourMechanic, run an inspection based on a door...

Q: Camry not starting

Hi there. No start conditions can be caused by a whole host of possible causes. Fuel pressure needs to be checked to ensure there is fuel available for startup and verify fuel pump operations. Power to the fuel injectors comes...

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...
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...