Passenger map dome light rear replacement needed

I am not sure this is the light itself as the flickering could just be a bulb and the dimming of the lamp could be a bulb or a loose ground.

When you checked the voltage, did you get a measurement of how much voltage you have at the lamp? Did you check the voltage on the ground side? A loose ground will normally pull voltage from the bulb so it is worth checking. I included a wiring diagram below and here is a guide that will help with this:

https://www.2carpros.com/articles/how-to-check-wiring

I also included the testing for the lamp always staying on. Basically they are telling you to replace the bulb which is what the solution probably is but I don't think you need the entire unit. The bulb appears to just be replaceable when you pull it down.

Please review the attached material below and let me know what questions you have. Thanks

Interesting. If it is not the ground wire then monitor the voltage while they are acting up and let's see if that is consistent. Thanks