Review on 🔧 High-Quality Replacement Xenon HID Ballast for BMW, Mercedes, Audi, Land Rover Headlight Control Unit Module - Replaces 307 329 074, 63127176068, 307 329 090, Others - Extended Warranty by Brandon Micali

Also known as VW's 'Range Control Module', this ballast is an exact replacement. If you don't have a headlight on one side, switch the working bulb to the side that doesn't work; If that doesn't work replace the igniter and if that doesn't work you're probably looking at the ballast mounted on the underside of the headlight assembly. You should remove the assembly. After removing the grille, unscrew all the screws on the TOP and 2 in the upper wheel well of the bumper cover, loosen the cover on each side by sliding the cover forward into the wheel well (leave the screws on the bottom of the cover, like this that It does not remove completely and pull down in front of each headlight to access a (F%$&@) screw hidden behind a cover on the bottom of the headlight, the other 2 (top outside and center inside ) are easier to access (any T-20 or 25 Torx) then disconnect the main power harness (large connector on the back of the headlight) It has small latches at the top and bottom of the connector that need to be squeezed to release, you will break they become very brittle, it doesn't hurt to reinstall as the connector has a strong o-ring that holds it perfectly.After removing the light assembly, swap the preview old device from the good side with the bad side. Push it back into the hole far enough to insert the wire harness and see if it works. You need these ballast spas at a great price, Ronnie.