98 4x4 sc 5.4 new battery new alternator I've checked all fuses replaced the 175 mega the last alt I put on was bench tested before installed had it checked after I put it on and the test said the voltage regulator failed could I have a problem in one of the pig tails on the other connections

 

new doesnt mean good

 

I recommend either taking it to Ford. Or go to an independent battery shop that can do alternator and battery maintenance and system testing.