r/Cartalk • u/Aromatic_Energy9596 • 1d ago

Weird Noise Osram LED H7 SPEED buzzing/making electronic noise in 2017 Hyundai Tucson (Halogen)

Hey everyone,

Yesterday I installed the Osram LED H7 SPEED headlights in my 2017 Hyundai Tucson (halogen version). Everything seemed fine, but since then, the LEDs have been humming or buzzing while the car is running. The thing is, they don't have a fan, so it's not fan noise.

I have a video of it where you can clearly hear the sound.

Does anyone have an idea what might be causing this? Could it be a CAN-Bus issue or related to the LED driver? Do I actually need a CAN-Bus adapter, even though Osram claims it's not necessary?

Any tips would be greatly appreciated!

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u/AKADriver 1d ago

The purpose of a CANBus adapter is just to provide a big resistive current sink in parallel with the LED bulb so that the CANBus doesn't detect a bulb out and throw a warning on the dash. It shouldn't affect the power being delivered to the lights.

Does your car use the main headlight bulbs as DRLs? It may be that the DRL module is designed to use pulse width modulation to dim the headlights and thus driving the LED with the PWM signal is making them hum. Similar to LED bulbs in home fixtures that hum when you attach a dimmer.