When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I noticed today that while the engine was running, if I had the incandescent dome lights on, they would flicker almost in harmony with the RPM of the engine. With the engine shut off, they would go back to normal state of not flickering. It just weird and clearly related to the alternator, but does anyone have any knowledge of what specifically might be occurring? One thing to not is there is not error codes stored relative to the alternator or battery system.
I noticed today that while the engine was running, if I had the incandescent dome lights on, they would flicker almost in harmony with the RPM of the engine. With the engine shut off, they would go back to normal state of not flickering. It just weird and clearly related to the alternator, but does anyone have any knowledge of what specifically might be occurring? One thing to not is there is not error codes stored relative to the alternator or battery system.
If you have a conventional flooded battery, be sure the electrolyte level is proper. If so or a sealed battery, have it load tested as it may be near the end of its' useful life.
If you have a conventional flooded battery, be sure the electrolyte level is proper. If so or a sealed battery, have it load tested as it may be near the end of its' useful life.
Funny thing is I just replaced it a few months ago. Audi battery and I made sure it was coded properly.
I would guess some sort of a bad ground issue. First I would make sure your battery connectors have a solid connection since it was worked on recently. Then its a process of figuring out what your light ground distribution.
FWIW, mine have slightly flickered on the early-build beige car since I've had it. More pronounced when the lights are dimmed, but unless you look at the lights themselves it's not noticeable. This is only the cabin (dome) lights so I deduced it is the dimmer circuitry.
I'm pushing my luck on its battery, Bosch brand I think, it's been in there >5years and I let it run down a couple times. But my battery reconditioning charger says it's 90% and car says 100% except if I leave ignition on for hours, then I've seen low as 60% (car starts fine).
I finally got curious and poked around with VCDS and used the graphing function to look at terminal 30 voltage from the Roof Electronics module, found that the voltage was fluctuating between 13.45-13.55 volts. When some throttle was applied, thus raising the RPM the voltage stabilized at 13.55 volts and the pulsating, fluctuating light stopped. Here is the graph below which shows the fluctuation in voltage and stabilization with increased RPM.
I will adjust the scale tomorrow and re-upload the image tomorrow.
Bump, having this same issue. Tested the alternator and it said excessive diode ripple, so I replaced the alternator but the light flickering issue still remains.
01-29-2017, 05:39 PM
Flicking Interior Lights (non-LED)
