On the wiring diagram they are labeled going to "interior light system". I tried to find out where they go with no luck. Does anyone know?

 

according to the real volvo schematics (I hate those mitchell things), MCC (manual climate control) pin 13 is a blue wire that goes to 5/1 B:1 via connector D1 pin 1, and MCC pin 11 is a white wire that goes to 5/1 A:5 via D1 pin 3. connector D1 mentioned above is a 4 pin block connector that looks to be right behind the MCC control panel.

5/1 is the instrument panel, connector A is behind the tach on the top, while B is below it, both of these are horizontal connectors. instrument panel pins A:5 and B:1 are the instrument panel and dashboard dimmable lighting circuit as driven by the rheostat

 

Thanks! With your info, I found it also goes to the blue ashtray bulb, which by the way, the price of that bulb is ridiculous!