Have a strange issue, interior lights go on. 2nd one goes on, than both is dim. I have checked the fuses #47 & #86. Both in order.

Anyone can help?

 

what year S40? Sounds like a ground issue or a switch issue (ie dirty contacts)

 

Did you check all the fuses?

 

To be honest, only #47 & #86

Will give it a bash and check all. Will let you know the outcome. Hoping to find the faulty 1

Thanks.

 

Were you able to solve your problem? I have a 2005 S40 and the same problem just started. With one interior light on (either front or back), it is bright. But a second light on causes both of them to dim. I've checked my fuses as well.

 

Bad ground somewhere. Might be difficult to find though...

 

I checked the fuses again. There was an additional one that was bad that I had missed. In the end, I had to replace two 5A fuses. Now it all works. Thanks!