I have a 99 C43 with Xenon headlamps. The driver's side headlamp was out. I replaced the bulb. It came on, but stopped later that day. Sometimes when I turn on the headlights, it comes on. Sometimes it doesn't. So I figured it was the ballast. I talked to a local dealer who said that the "headlamp controller" was part of the whole headlamp assembly (big bucks for what I thought was just a bulb). Then I found something called a "headlight igniter" (P8014-97727) on a MB parts web site for about $100. Is that what I need?