4 Wheel Drive/SUVs: electrical issue 2002 chevy trailblazer

Question
I have checked all fuses and relays and grounds i can get to i replaced the neg cable as it was bad now the problem no door locks no interior lights no electric windows not starting guages not working lights on dash work as well as turn signals but lights on dash dim when ignition switch is turned to start position battery replaced could it be a possible bcm problem and where is it located

Answer
Mike,

The only way to check this out, is to get a voltage meter, and start tracing out the wiring.  Start at the battery, and work towards the fuses.  Check the voltages by trying to start the vehicle and see how much of a voltage drop you get.  I would suggest that you purchase a repair manual from your local parts store, as they have wiring diagrams in them.

There is no real easy way to check this out without tracing out the wiring.

I have seen this problem many times, and the solution has been everything from a faulty battery to a loose wire connection not letting the full voltage through.  Any type of short, or bad connection can cause this.  I had a similar problem in my Grand Cherokee, and it was a broken ground wire in the wiring from the body to the door.

Carl