Volvo Repair: Dashboard Lights Not Working, dashboard lights, volvo 240

Question
Hi!
I have  Volvo 240 1991, my two main lights on back of dash do not work. When I turn lights on blinker indicator arrows go on and stay on but not dash lights. Light went out when I tried to wire small clock and I think I reversed  the wires, there was a small spark when I connected the wires. Is there a some voltage regulator or something else that could burned out that would cause this?
Thank You!

Answer
Zoran, there are 2 bulbs there.  Take them out and see if it burned.  you may have zapped the dimmer switch.  I would have to take the cluster apart and check it for you.  The Voltage reg on these clusters is the temp compensation board that controls the fuel and temp gauges.  Roger