Volvo Owners Club Forum - View Single Post

SwissXC90 · Nov 19th, 2018, 15:26

It's not a ballast resistor.
It's there to sink the leakage current which occurs in electronically switched lighting systems when you do not use an incandescent bulb.

So you just need to provide a resistive pull-down path to ground, and it doesn't need to be much.
You could probably get away with 10kOhm

You definitely do NOT want anything like 470 ohm which would start to get warm.

The goal here is to pull-down with the least amount of current possible, and thus the least amount of power dissipation.

Nov 19th, 2018, 15:26	#17
SwissXC90 Premier Member Last Online: Mar 20th, 2024 18:26 Join Date: Jan 2016 Location: Cross Country	It's not a ballast resistor. It's there to sink the leakage current which occurs in electronically switched lighting systems when you do not use an incandescent bulb. So you just need to provide a resistive pull-down path to ground, and it doesn't need to be much. You could probably get away with 10kOhm You definitely do NOT want anything like 470 ohm which would start to get warm. The goal here is to pull-down with the least amount of current possible, and thus the least amount of power dissipation. __________________ XC90 R-Design MY2009, Black Sapphire Metallic. HP-Sound, RSE, Nav, Tel, ParkingCam, BLIS, ParkingHeater, RestHeat, Removable Towbar, Summer: CRATUS 20x8 on Pirelli Scorpion Zeros 255/45, Winter: NEPTUNE 17x7 on Continental WinterContact 4x4 235/65.