Lost all my electrical in the cab no head
lights, instruments,brake lights nothing
works.battery is charged new alternator new
starter new harness for batt/starter. .both
fuse boxes and fuses are all good..
Begin with a multi-meter at the fuse boxes and check for voltage at each fuse controlling the items which do not work/function. You have to find where, within the circuits you have voltage, then check backward to find the problem.
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