On the newer Volvo units, when the battery is dead in the alarm module, the sunroof locks out. Not sure if that would apply to a 97 model but at a minimum it is a lead for you to pursue.

 

Hello everyone,
I have been reading about this issue what other people have. Mine is different.
When cold in the morning Sunroof and Map lights work, but when the car gets hot it does not.
The alarm works.when I press it on the remote.
Could someone give me some hints?
Thanks you in advance.

 

Heat causes the Wires to loose connection inside switch?

 

+1 on heat causing a connector, switch or a relay causing a circuit to open up. You'd need to look at the wiring diagram or relay/fuse layout to see where the sunroof and map lights have common wiring/fuses/relays/ground points then test (a can of cold spray or compressed air can help by cooling off a component to see if the circuit closes as the device chills.)