I have 94 2500 that has no running lights or dashboard. Checked fuses and pulled 2 relays on right to check and they don't affect. There is smaller relay on left that I can't pull out. Is this the dimmer relay. Is my problem with the light switch because I have all other lights, head, backup, turn, and brake.

 

Did you try turning the ****? A rheostat is used to dim the lights, sometimes they get dirt in them and don't work. Take the switch out and have a look at the terminals/harness on the switch. They have had issues with them heating up and melting.