1990 suburban wiring issue
 

I picked up a 1990 Suburban, and have few issues, the radio only works when the doors are closed, then noticed glove box lamp only works with doors closed, same with horn, open a door and glove box light and radio lose power. also overhead console reading lights only work one at a time, weird.

started at the fuse block, and checked ALL fuses, notice the orange wire at BAT on fuse block feeding radio only has power when all doors are shut. same with clove box light.

Check white wire going to front door dome light switch and have 12v on it, it has got me stumped, frustrated and now can not think right.

Seems the opening of the switch/closing of the door powers the BAT terminal at fuse block where orange radio wire is.

It did have an alarm installed, removed it and same thing happening,

I also checked for power on firewall, and fuse links, found battery wire on alternator was broken and repaired that but again same thing.
I am getting frustrated at it and myself, need second set of eyes if you will.

And howdy from JOPLIN MO.

Re: 1990 suburban wiring issue
 

Behind the dash (instrument cluster) on the A pillar is a grounding block where about 4-5 wires are connected to a spider looking thing. May want to see if that is loose or dangling

Re: 1990 suburban wiring issue
 

x2. Someone probably disrupted the original ground circuit when they installed the alarm. I would look at any place the wiring has changed and go from there.