Afterglow Relay Causes Flickering Lights

A few weeks ago, I replaced all my glow plugs because they were all defective.

During the afterglow phase, the relay deactivates the afterglow if the engine speed exceeds approximately 2500 RPM, and reactivates it once the speed drops below 2000 RPM. You can actually hear the relay switching on and off quite loudly.

With the new glow plugs, I'm now seeing a relatively strong flickering of the light at the moment when the relay switches. I can explain this by the fact that with now perfectly functioning glow plugs, a high current is being switched on and off.

The flickering is very strong; you can clearly see it on the street from the low beam headlights. I worry about the H7 bulbs every time.
Is this flickering normal, or does it indicate other problems (e.g., voltage regulator, ground connections, battery, relay)?
I don't remember ever seeing that before, but it's probably because my spark plugs haven't been in good condition for a long time.

Of course, I understand that high engine speeds should generally be avoided, especially when the engine is cold. Unfortunately, it's not always possible to avoid them for short periods when accelerating on the access lane.

"I experience the same thing. I consider it normal, as four working glow plugs draw a significant amount of power, especially since the other three should also be on."

A voltage drop shouldn't damage the H7 bulb; voltage spikes, vibrations, and cost-cutting measures by manufacturers are likely to be more problematic. The main thing is that the numerous control units can handle it.

Best regards!

"My TDI also has this flickering light issue - ever since I installed the new spark plugs."

For me, I can even hear the relay clicking noticeably, and I consider it normal.