Chevrolet Repair: 2004 Chevy suburban Z71, suburban z71, trickle charger

Question
So my 2004 suburban wont start.  The dash lights all light up and all accessories work however when I turn the ignition switch all I get is a "click".  I took the car to a local mechanic that I trust after multiple attempts to jump start it, and they told me my alternator was failed(putting out voltage too low to effectively charge) and that our battery was shot because it tested failed on their computer(575 CCA) on an 800 CCA battery.  So I had them replace the alternator and I bought a new 800CCA battery and installed it and still, "click".  The shop was able to get it running after charging the old battery up to the 575CCA but the next morning before I could replace the battery, I was unable to start the car again.  Same click.  So after replacing the battery I put the new battery on a trickle charger for a couple of hours and fully charged it, still "click".  Now I have done a lot of reading of various forums to try and diagnose this issue and am unable to find a solution that makes sense to me?  Some people have replaced fuel pumps(but my car isn't even trying to turn over) some have replaced starter assemblies(why would the mechanic have missed that?) some are having problems with their passlock security system(my security light does not stay on as other's lights have?) all I get is the "check engine" indicator light and the battery light.  I have tried the recommended reset procedure for the passlock and am worried that this will end up becoming some phantom problem that costs me thousands with no definitive solution.  Please help.  -Marshall

Answer
HI MARSHALL, THE WAY YOU ARE DESCRIBING THIS TO ME IT SOUNDS TO ME LIKE A BAD STARTER, PERIOD.
THE PASSLOCK SYSTEM WOULD NOT LET IT CLICK.. A FUEL PUMP WOULD NOT DO THIS, THE ENG WOULD CRANK FINE, BUT NOT FIRE..YOU HAVE POWER TO ALL, BUT NO CRANK [JUST CLICK AS YOU SAY]YOU NEED TO GET UNDER THIS TRUCK WITH SOMEONE IN THE TRUCK WHEN THE PERSON IN THE TRUCK IS TURNING THE IGN KEY TO CRANK POSITION YOU NEED EITHER A TEST LIGHT OR A VOLT METER TO CK FOR POWER AT THE STARTER. YOU WANT 12 VOLTS ON THE BIG WIRE TO THE SOLENOID AND 12 VOLTS ON THE SMALL WIRE ON THE SOLENOID EVERYTIME THE KEY IS TURNED TO THE CRANK POSITION..THE BIG CABLE IS FROM THE BATTERY AND THIS WILL HAVE 12 VOLTS ALL THE TIME EVEN WHEN THE KEY IS OFF. THE SMALL WIRE ENERGIZES THE SOLENOID TO ENGAGE THE STARTER..AS FAR AS YOUR TECH NOT FINDING THIS IS BECAUSE THERE IS A FLAT SPOT ON THE STARTER ARMETURE. SOMETIMES IT WILL CLICK AND SOMETIMES IT WILL CRANK OVER.[[THERE IS A TEST FOR THIS WITH THE CORRECT TOOLS]]THEY SHOULD OF CHECKED THIS. USUALLY IF THE ALTERNATOR IS BAD THE ENG WILL JUST DIE AND ALL ELECTRICAL SOURCES WILL DIE AS WELL. ARE THEY SURE THE ALT WAS BAD ???? I HAVE MY DOUBTS. IF YOU DO NOT HAVE ANY TOOLS AS ABOVE, HAVE SOMEONE HOLD THE KEY TO THE CRANK POSITION AND YOU TAP THE STARTER WITH A HAMMER [TAP NOT HIT HARD] IF IT CRANKS LIKE THIS THE STARTER IS BAD. THIS IS A 50 50 TEST NOT AS GOOD AS A VOLT METER.  NOW LETS SAY YOU DO NOT HAVE 12 VOLTS WHILE TURNING THE KEY TO THE CRANK SIDE OF IGN ON THE SMALL WIRE AT THE SOLENOID YOU MAY HAVE A BAD IGNITION SWITCH OR WIRE PROBLEM..MAKE SURE THAT THE BIG CABLE ON THE STARTER HAS BATTERY VOLTAGE ALL THE TIME,IF NOT FIND THE PROBLEM ,SUCH AS CORRODED CABLES OR FAULTY GROUND CABLE TO THE FRAME..I HOPE THIS HELPS YOU AND LET ME KNOW HOW YOU MAKE OUT,,, GOOOD LUCK..TOM