Dash lights, Marker lights, Radio, Bad electrical problems.

[Sills]

Hey, Unfortunately I keep coming back to this forum to find fixes for my S14 Silvia which keeps acting up. I have a few obvious electrical issues however im not sure if they are related. Id like to fix them all anyways so any insight to an issue is appreciated.

Back very early this year my car started having a strange interaction with the brake and front right signal light. My brake pedal when depressed is for some reason partially illuminating my front right turn signal. The bulb and dash indicator both glow, when I signal right to turn and brake the light will sometimes not flash only when the brake is down or will flash quickly while I brake. Not my biggest concern however I wonder if it might add a clue to my new much bigger problem-

A few days ago after work I went to drive home and my dash lights were not working. When I got home I realized that my tail lights and front markers were not working either. I did a quick search and read that this could be caused by bad wiring behind the dash or radio. I pulled the dash out and nothing seemed unusual. No burns on the circuit or anything. I recently installed new leds. I put it back and went to investigate behind the radio. (Double din kenwood). Ive been back there before and knew that the previous Japanese owner did a questionable job on the radio wiring (However still unsure if there is even any related wiring to my dash light problem back there) I cut the wires on the cig lighter so I could move the whole radio piece aside easily then taped some connections up. Did not reconnect the cig wires as I dont use it anyways and figured id do that at a later date. There were 3 wires I believe, including a blue and red one I believe which was for some reason spliced into another factory looking wire, with a non-factory looking wire splice... Anyways once I plugged the radio back in that no longer wants to work either. I checked the kick panel fuses and found 1 blown. Replaced it, dash lights flickered on for a second then the fuse popped again.

I picked up some solder and heat shrinks today and im going to be attempting to clean up all the messy, poorly connected wires back there to start although I am doubtful that it will help. Does anybody know of any note worthy wires located in that area?

When I put in my new ecu with my rb swap I noticed another possibly non factory looking wire marked "Battery". It is brown and has an inline fuse. I just left it however the car has been driving very well for a couple months now so I doubt thats the issue.

The other day my car randomly died while driving (After all these wiring issues came up) It had no power which didnt surprise me as the battery was fairly garbage after being driven to death on a shitty alternator that I just replaced. I replaced the battery yesterday and the car was boosted, made it home and the car still had power after. No power this morning however I still have that big clump of messy radio wiring hanging out.

I understand that this isnt a post about stretching tires so there probably wont be very much useful information out there. Any suggestions are appreciated though. Ill continue posting as I troubleshoot and work on it and if im lucky maybe have a solution before I have it stored for winter. Thanks.