Guage lights don't work

[Claybraham]

i tried searching for it and I'm pretty new to the site. I have a 1990 gmc and my dash lights will not come on. First I pulled the cluster to check the bulbs but there isn't any lol. I replaced the lights switches and the dimmer switch and still nothing. Any suggestions? All gauges work, my lights just won't come on when I hit the headlights. Thanks in advance!!!

 

[GL1500]

Check the fuses. Your owners manual should tell you which ones to suspect.

 

[Claybraham]

I checked them, they are good. Thank you for the reply!