I have a good understanding of electrical I'm just looking for components amd locations of them


My problem is when I got the blazer 2 days ago I was told the dome lights haven't worked because the dash was removed turns out there was no fuse in it. I put a fuse in and it worked fine I was happy lol. So after blowing 4 fuses I discovered that by opening the front passenger door the light dims for half a second then blows

My question is the door switch a ground like most cars? is this a known issue? Did the person who did the heater core a person who shouldn't have? Maybe a component is the problem and just needs replaced?

All 3 other doors work fine with dome

I'm not new to working on cars. I did Google this issue. I'm looking for some advice before I attack it because I have never worked on a blazer and mine has power everything I'm trying to build some knowledge before hand
also side project power mirrors don't work until I got it too move for a split second then nothing