Rear tail lights won’t go off when the car is turned off

[KathyW]

Two nights ago my C-Max had the rear lights staying on, even with the car turned off. It is the rear drivers side light and the light on the tailgate. Oddly enough, it didn’t happen to the passengers side light. We tried everything to get it to turn off. After a bout an hour of tinkering, my husband got them to go off, but sometime in the night they turned back on and stayed on until the battery died. Of course we can boost the car, but that won’t solve the problem. Has anyone else ever had this happen? Any ideas how to fix it?

[homestead]

Test the brake, turn signals and backup and running lights to get a better idea of what is working and what is not.

May just be a bad bulb on one side.

[nogoodbum]

In your other post, you said the car was a 2014 that has had no prior problems. Assuming that you are still on the OE 12v battery, I would check & see if or how weak it is after 9yrs. A weak 12v battery is notorious for oddball effects prior to failure in the C-Max. Do check the bulbs also as if one or more may effect the timer that shuts them off. Thanks for the read.

[LisaV]

I have the exact same problem with my 2014 cmax. I had my battery replaced because I was told it was bad. I had notice the tail light in passing before I took it in to be checked. I assumed it was just slow in going off. After the battery replacement it's still doing it. But now I am also having trouble with my lighter charger not working and not being able to connect with the bluetooth.  Just a bunch of weird stuff.  I don't know where to start troubleshooting. I am now also getting a warning light for a powertrain or high-voltage charge system fault after I jump it.  But then it goes away.