Interior dome lamps work only part of the time

Fedexman · Post by **Fedexman** » 11 Sep 2011, 22:38

I just got my s80 about a week ago and since I got it I have learned that the dome lights and the home link lights only work if you pull the number 28 fuse out and replace it. Over a period of about 10 minutes they go out completely again and you have to repeat the process. When I got the car the dealer had just replaced the rearview mirror, I was wandering if anyone could help me with my problem and enlighten me on this issue? thanks so much

voltech1 · Post by **voltech1** » 11 Sep 2011, 22:59

The rearview mirror is called the UEM and needs software loaded into it to communicate with the rest of the vehicle. It is possible the dealer did not download software when it was replaced. That would explain why it is going offline. If you have the invoice for the mirror the part and the software would show up separate. I would start there and maybe someone else can be of more help because I dont know why the homelink would lose power supply to it because of that but maybe it would. Some dealerships will work with you $$ on diagnosing this especially if you are a new customer coming in.

Fedexman · Post by **Fedexman** » 12 Sep 2011, 00:09

I appreciate your help, The guy that I bought it off of is a used car dealer, would I have to go to the dealer to get the software I need? After all this is a used car for work purposes only and the less I spend on it the better off I am. I don't have to have the dome lights if you know what I mean!

cacvolvo · Post by **cacvolvo** » 02 Sep 2012, 23:50

Did you ever get this working? I am having the exact same issue with a 2002 S80 I just purchased. The sunroof does open and close, but there are no lights. When I pull the #28 fuse and re-insert, all the light come on, but stay on when the doors are closed. I can push the buttons and the lights go on and off as the should. After about 10 minutes, they do not work again. So...what was the solution to your dilema? Thanks

Post by **yuckuJackD** » 10 Sep 2012, 15:14

Just find your old rearview mirrors, and replace only the glass from the new ones. this way you avoid any need of costly software.
Search around here. You'll find a step-by-step tutorial with pics for all the steps needed from removing the old, replacing the glass and installing all back in place.
GOOD LUCK.

Rocky · Post by **Rocky** » 10 Sep 2012, 15:27

Could the switch be worn?

cacvolvo · Post by **cacvolvo** » 29 Sep 2012, 21:18

Found answer to this one. The UEM (Located inside the Rear View Mirror) is not functioning. In my case, the car I bought had a used UEM in place of the one that should have been on the car. According to Volvo, UEM's can not be swapped between cars and can never to programmed to work on a different car due to the fact that the UEM controls keyless entry. Pulling the fuse just resets the UEM that is there momentarily, but when the UEM is not recognized, it simply times out and stops functioning. A new UEM should fix the problem. They are expensive so shop around and make sure you have your VIN number when getting quotes to make sure it is the right UEM for your car's system. Once installed, the dealer will need to install software and program your keyless remote into the new UEM for it to work also.