Skip to content
View in the app

A better way to browse. Learn more.

Ultimate Subaru Message Board

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Turning headlights on makes car die?

Featured Replies

93 legacy wagon awd 5-speed 260k+

 

Just started happening :

 

On cold start if I turn the headlights on the car will stumble then die.

 

Restarts everytime.

 

After warmed up it wont die but it will make the idle stumble for a second.

 

Lights work fine. No Drivability Issues.

 

Alternator puts out 14volts while running and 0.02v A/C so its good.

Battery Tests good, I even swapped it for another one just in case.

Battery Cables and Terminals Clean

Added more ground wires in the engine bay

Cleaned IAC

 

 

I'm lost here, anyone else out there had this issue?

Are those voltages w/headlights on?

 

Measure AC at the alt. rather than the battery.(headlights,heater fan on full,revs up)

Perhaps the headlight is causing some sort of a short.

 

The headlight bulb holders used to melt with some regularity.

 

Otherwise Cougar may chime in. He seems to have the knowledge/patience for this wireing stuff (just my observation).

That alt voltage is meaningless. Get the engine up to 1800 rpm. Since you have an issue we will do this a little differently then usual.

 

The goal is to have EVERYTING on in the car and have someone read the voltages. STart with the Stereo, then record the voltage, then the blower, then the AC compressor, the rear defroster, the wipers on high, then the lights, parking first, then headlights last.

 

Normal test is to get everything on rev the engine to 1800 rpm and look at the output.

 

It sounds like a borderline alt to me.

The headlight bulb holders used to melt with some regularity.

 

+1 to that, mine was blowing fuses every time I turned on my high beams, of course I found this out at night...

+1 to that, mine was blowing fuses every time I turned on my high beams, of course I found this out at night...

 

or when the cop pulls us over :-\

If the alternator checks out, this could be a mechanical issue. Cold idle fuel mixtures are important. If the mixture is off the engine will not be able to handle even a minor load. Even something as seemingly insignificant as taking your foot off the clutch pedal can stall the engine. Turning the lights on makes the alternator work harder creating a load on the engine.

This can be caused by anything from something like a vacuum leak, to a slow/sticky idle control valve, or a bad temperature sensor.

When was the last time you gave this car a tune-up?

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.