When looking at my 2002 SC430 up close, I noticed my day time running lights are flickering very slightly (when the car is parked, not sure when it's driving). I only notice this when analyzing them closely.

Is this normal?

 

It's hard to understand what you consider flickering without seeing it ourselves. I don't notice any obvious flickering with my DRLs. . And to be clear they are OEM bulbs and not LEDs right? Because there is an issue with flickering LEDs.

 

VVTiBob, my daytime running lights are entirely standard factory OEM, not LED.

It is only noticeable up close, from about 10 feet away you cannot see the flickering. I wonder if this is an "early warning sign" that my alternator or battery is on its way out.

Thank you

 

With the "up close" but not far away it doesn't sound like the issue. But you can easily test those two components with a meter, with and without a load.
You should also check the accessory belt for tightness and cracking. If the car ever squeals, it needs to adjusted or replaced.
For the battery, check the voltage when the engine is off, not when the alternator is raising system voltage to its normal level. You can test for proper cranking voltage with a voltmeter while—you guessed it—cranking the engine. The several hundred amperes of current the starter motor draws should pull the battery voltage down to a normal 9 to 10 volts. Do this test: Disable the ignition or injection to prevent the engine from starting. Then put a voltmeter across the battery posts while cranking it with the key or an external remote starter button. Crank for 15 seconds (no longer); the battery voltage should remain 9.6 volts or above.

 

Does this occur only with engine running? If so, perhaps diodes or other components in the rectifier (alternator)? If only with engine running you should check and see if the voltage elsewhere in the system is fluctuating when the car is running (hence the pulsing of the lights), in which case you are not getting the alternating current (from the alternator) completely rectified (and filtered) to produce the desired DC current. Are the rectifiers integral to the alternators (I think so)? If it is only the lights that are pulsing, and the voltage elsewhere is fine then it is a light component issue.

 

Mine does the flickering, too. Not bad but noticeable.

 

Thank you to everyone who responded. I will first check to see if I e the flickering with the engine off.

I will then follow VVTiBob's instructions and purchase a voltmeter to perform more involved testing to see if I can narrow this down. This isn't a "biggie", but certainly something I'd like to diagnose if I can.

In thinking about this, maybe I should have asked the dealer to disable the day time running lights during my last service appointment , to avoid the whole issue

Thanks again

 

Check my 02 this morning and the DRL's indeed flicker (modulate) very slightly when running at idle speed. Doesn't worry me in the least.

 

I have slight "flicker" as well but wonder if it has more to do with engine vibration .. going in to have the motor mounts looked at this week anyway. Once I solve the vibration problem will take another look at the DRL's.

 

It was the motor mounts. DRL's are fine now (although yellow, would love to update). What looked a lot like a flicker was vibration at idle.

 

UPDATE:

I had my motor mounts and transmission mount replaced, but the daytime running lights are still flickering. I guess in my case it didn't have to do with the engine vibration. I decided to ignore this and forget about it for now... unless of course this is a sign that my alternator is about to go out, in which case I will update this thread.

 

Hi All,
The Oem DRL is flickering in my car since New, I change to LED with relay now,but still flickering a little bit when idle .
My friend dive in front of me said didn't see flick when the car move.

 

Noticed this on my 03 as well but havent done anything about it.
But again...another reason why this forum and all its members make owning car and solving any issues quite a bit easier. Thx

 

they all flickers from my experience. change new bulbs it should fix the problem. if not, your DRL resistor is not good, but doubt it.

forgot to mention make sure battery is in good condition, as in passes the battery load test.

 

I changed to LED with relay now,but still flickering a little bit when idle .
but no flick when the car is running.