'88 Suburban lights don't work right

got an '88 suburban and all the lights worked when I got it all I've added is a CD changer and it had nothing to do with the lights, now the panel lights, taillights, lescinse plate light, interior lights, and running board lights don't work. headlights high/low beams, turn signals, flashers, brake lights, and reversve lights all work fine. I checked fuses and replaced the light switch yesterday and had to effect can anyone please help?

Thanks for a complete post-it seems you have lost the parking light circut-does this truck have 1 fuse box under the dash or 1 under the hood and 1 under the dash? Double check your fuses with a test lite,the parking lite circut should be "hot" at all times.If you have power at the fuse and no lites you have a wiring or connection problem to or after the switch.If there is no power to the fuse you have a problem with the feed. Buy a $15 manual and it will give you basic wiring diagrams. This is the best I can do without testing it myself,yell back if I can be more help.

I'm on the same page with you I've got the Haynes Repair manual and I've been staring at the extior light diagram and there's 3 fuses on it but I only see "panel lights" on the fuse box under the dash and I don't know about one under the hood I'll have to check. I just got back from buying a test light and the fuse is good but I still need to see if the fuse is getting power. thanks for your help I'll keep trying

T/L and ctsy share the same fuse. I think you have blown fuse