What does this button do..

[wyle.e.kyote]

Not an Angola owner but, # 2 looks like the heated morror switch and #5 looks like the back up alarm shut off. Is # 4 Gauge lights??

Congratulations! #2 does appear to heat the mirrors and #5 does cycle the backup alarm. Many thanks!

#4 doesn't change the panel illumination though, I found that one as the Engine Stop Override according to the pdf I downloaded off the volvo site for a different bus. "Press down this switch and release to override emergency engine shut down protection. Engine emergency shut down will be turned OFF for 30 seconds. This procedure can be repeated if done before the 30 seconds are up."