Right headlight power issue -- any experts?

[skrenes]

Hi everyone. I noticed just a couple days ago that my passenger side headlight was having power issues. Sometimes when I signal right, the light would blink twice as fast and make no sound in the car. It seems to be getting worse and now my air suspension light is on. When the headlights are turned on, it also shows on the avatar that I have no right headlight.

When the power returns, the air suspension works properly and the warning light goes away. So it sounds to me like there is a loose or corroded wire somewhere. Before digging around, I was wondering if any resident experts have suggestions or if this has been seen before.

Thanks so much for any help!

 

[Azathoth]

I had exactly this happen on a new 2020 MS Raven two weeks after delivery - the passenger side headlight wouldn't light and the right turn signal flashed 2x normal with no sound or indication on the CID.

Mobile service came out and tried to replace the complete headlight assembly (not a simple task), but that didn't fix the problem so I had to schedule an SC visit. Took them a day to diagnose the problem which was a "loose/corroded ground wire" that they simply tightened.

That fixed the issue for about two weeks, but then it returned on a hot day. I scheduled another SC visit but on the day of drop-off it was working again so I asked the service manager if I could just bring the car back the next time the issue resurfaced. That was three months ago and so far the headlight and turn signal have been working normally...

 

[skrenes]

Thanks for replying. Shocking that your new Model S would have this issue! Sounds like it was not tightened rather than lose. Does your service invoice contain any clues as to which ground wire? I'm really hoping I don't have to take too much apart to trace the wires leading from the headlight. The fact that air suspension is affected makes me think it's a common ground wire. I'll definitely post back what I discover in case this happens to someone else. Perhaps it'll be helpful to your SC.

 

[Azathoth]

No details in the service notes on which ground wire was tightened. What worries me is that the issue returned for a day AFTER the ground wire fix, then went away on its own. I keep waiting for an unwelcome surprise if it crops up again.

Beyond that, I'm still experiencing another problem with the headlights turning on in full daylight (Auto mode) when the outside temperature is over 92°F. I just manually turn them off when it happens, but it's a PITA.

BTW, this is my second Model S; the first one (a 2016 refresh) was flawless for nearly 4 years.

 

[skrenes]

As a follow-up, I managed to fix the issue. I pulled the front trunk tub out and underneath it are two grounding points on both frame rails. I unscrewed them, sanded them down and wire brushed the terminal. Then applied dielectric grease and screwed them back on. All the issues have gone away and never come back!