Why does my car die when I turn on the headlights?
Everything immediately shuts off, including the engine and dashboard lights, as soon as the headlights are turned on or the vehicle attempts to crank. Even though the battery is fully charged and the alternator is working, the car simply refuses to start and is completely unresponsive to being jumped. This total electrical failure leaves drivers at their wits' end and unable to use their vehicles.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Replacing the battery, alternator, and starter
- 2Checking ground wires for parasitic drain
- 3Wiggling the battery back into place to restore the electrical connection
- 4Checking the resistance between the battery negative and a good metal ground
- 5Measure the voltage between the positive terminal and a ground point on the engine.
- 6Check for loose or dirty battery terminals or ground wires.
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Recently my car has had some starting issues, hasn't happened that often but today it's just completely refusing to start. I got the multi meter out to check the battery, it doesn't appear to be the issue. When the car is attempting to crank all the dashboard lights go out.”source ↗
“as soon as i turn the headlights on everything immediately shuts off the engine dies and no lights.”source ↗
“the battery is still fully charged, as is the alternator and the alternators ground cable is 0.004. but its unresponsive to jumping it.”source ↗
“im starting to hit a wall here and im at my wits end.”source ↗
Where this came up
People with this problem also raised
- 2Why does my car make rapid clicking when I turn the key?
- 4High beams don't work even though fuses, relays, and bulbs are fine
- 144Vehicle cranks after fuel pump replacement but won't start
- 5Headlights turning completely off when switching beams
- 13Why does my car lose power for a second when starting?
- 3Why does my car die right after a jump start?