This might be nothing to be concerned about. You can check you refrigerant pressure.... it may be just on the hairy edge of being low, so the sensors will sometimes trigger. This may be one of those weird Volvo gremlins. My A/C lights did the same thing intermittently for about 2 weeks at the beginning of the summer, and it hasn't happened again. I didn't do anything at all... didn't even get around to checking pressures. I did get into the habit of turning off my A/C and running the fan on high speed for a couple minutes as I approach my destination... that blows all the condensation off the coil and prevents the build-up of dirt which can harden after it dries. The accumulation of such "stuff" in our highly polluted environment, can lead to early evaporator failure. If the A/C is blowing cold, and no other symptoms exist, be patient.... it may just go away. Good luck.

Marty
'96 855T