A family member has a 2003 A4 (1.8T Quattro) that's been experiencing some odd light problems lately. The car is a single owner, older adult, only 50k, taken care of very well. Recently, the front right headlight went out. Nothing abnormal here. The "check" button also verified this part, along with the obvious bulb being out. The owner keeps every single record, having been first serviced by Audi for 5 years and once the warranty expired, they went to one of the bigger garages here that is respected in the area. They replaced the front H7 and everything went back to normal.
Fast forward to about 3 weeks later and there is another "error" with the turn signal on the opposite side and the rear brake light on the same side as the light is on. I got a call and went over to check the error out. Nothing. No error, even after running "check". Turn signal is fine and the brake light is fine. After a week without any problems, I took a drive in the car for about an hour each way with the owner. Five minutes from home on the return trip, I get an error on the LED dash about the brake light being out. As we're turning onto their street, the right turn signal also starts to flash on the dash. In addition, the right turn signal went to a "fast" pulse, common when you lose the bulb. This, after being fine for an hour, I verified when we got into the garage. Driver side brake light is out and the right turn signal is bad.
I went to the car the next day, after sitting in the garage, to verify the errors and everything is fine. The brake light works and the turn signal is fine.
We're about 2 weeks from all of this and the family member has been doing their normal amount of driving (literally 50 miles a week, if not less) without any problems. No blinker problem, no signal problem.
This makes no sense, right? The only thing I can think of is some type of odd short in the car or the ECU is possibly going? And, it seems to only happen when the car is hot? The car has been driven since then, as I said, but none of the lights have gone out nor errors presented (the family member has been looking for them).
As I said, the car is 10 years old but never modified or abused. Anyone have a suggestion? I've yet to call up the shop they use to see if they can plug into the OBD and check the logs but I was wondering the best course of action.