2010 R56 JCW, 90,000 miles.

Having issues in medium to heavy rain, where the entire dash will turn off: radio, tach, speedo, all interior lights, etc. idiot lights for ABS, SRS, TPMS, all going crazy off and on again. When it's dry outside, I have no issues. If I drive on the highway in light rain, everything starts working properly again, but if the rain picks up, it's back to freakin' out. The car runs and drives while this is happening. Though the dash is going crazy, the lights on the outside of the car all work properly, headlights, brights, turn signals. The signals won't always click in the cabin, but they light up on the outside as usual.

Everything I've found on this site pertaining to these kinds of issues is BCM related, and I might be wrong, but I think that's only a first gen thing, right? There are no interior leaks that I can find, dry as a bone inside. I also checked the sunroof drains to be sure, and they all work fine. I was also missing some plastic in the engine bay area that I thought might be the problem (battery cover and wheel well foglight access door) but I have replaced these and it still has the same problem.

 

May have found the issue, I'll find out next time it rains. There was a loose ground on the drivers side under the kick panel, apparently the ground for all the interior electronics. I know because when I wiggled it, the interior lights all came off and on, as well as the dash electronics. Tightened up the ground, hopefully that was it.

 

Been a while since you posted this, but I'm having very similar issues. And hoping that since it's been so long, that means you tightening was able to fix it. I'm gonna have to try and look to do the same.

 

Hey Rain - yes, tightening that grounding point fixed all my electrical issues, I'd sand down the paint on the grounding bolt as well if I were you. I still have no idea why it was rain that caused flickering, because the module ground was dry when I found it, but I didn't experience that again. Too bad I never experienced the failed HPFP again or I'd still have the car haha!

 

Well, shoot, that sounds good to me. Thanks!