Generator circuit malfunction code
 

I have a 2005 f350 6.0 4x4 dually crew cab . I have dual alternators. I have done egr delete , oil cooler upgrade, straight pipe and use the sct live wire tuner. When I try to start it will crank and crank and no start until maybe 3 or 4 min after initial try. When I get it started lights, heater are working but low power as is if huge drain or low charge. I turn radio on and it shows readout but won't sound for like 30-45 secs then everthing comes on bright and working well . I have the 620 and 1000 codes. Wtf is it ? Alternator, Ecm , voltage regulator , ?