How to bench test my electrical wiring - Request

I am by no means an authority on this subject but, our cars have some weaknesses in the electrical system... especially at the firewall connector, examine this point for corrosion and heat damage, the amp gauge is often by passed and there are articles showing how to do this...the instrument cluster is another location that needs examination to determine if any connections are broken or corroded...I suggest also adding an auxillary fuse panel with some power adding circuits for accessories... after assessing your electrical harness , if you plan on adding several devices , a new aftermarket harness may be your best bet...