The right headlight went out on my wife's 07 Compass. I'm an electrical engineer with troubleshooting experience and figure the usual checkout sequence. Check the bulb. When I start to unplug the socket the headlight comes on. So it must not be the bulb. But seeing as it seems to be intermittent, I suspect the socket. I replace that (and did a fine job, I might say), but still no right headlight. Hmm, maybe the fuse. I search the internet, and previous jeeps had high beam fuses, and separate right and left low beam, but I can't seem to find a specific headlight fuse. There is one 30 amp that feeds the "module-totally integrated power" and I see another person that can't get the HID lights that they installed to work. So I start to have my suspicions. Then I see the "magic" canbus mentioned. Oh, oh... Called the dealer and figured the service rep will need to check his documentation, but no. Directly he agrees that is is a problem with some module. That we can bring it in, they read the error codes, and reprogram. It will only be $99.50! Progress, hunh!?