Strange electrical problem all electrical circuits dead.

[FellowTraveler]

Subject vehicle 1999 GM Suburban K2500 6.5td.

I was out this morning no issues came home parked the Suburban, go out @ 13:30 hrs and insert key in ignition turn it I get shifter indicator turn on momentarily then off and not power to dash cluster or anything else not even headlights however when I closed the drivers door the times it locks w/o me hitting fob and now the locks don't work either.

The batteries are fully charged.

I suspect the anti-theft system but don't think it would shut all power down.

 

[WarWagon]

Bad connection to the batteries. (Example loose positive bolt at the battery.) Possible ignition switch.

Do the dome lights work? If not suspect grounds then loose/bad/corroded/bad fusible link positive lead to main fusebox under the hood. With lights on hit major positive connections with voltmeter till you find the outage.

 

[ak diesel driver]

have you checked the power center fuses?

 

[FellowTraveler]

Thanks for the replies, I found 3 loose battery cables I suspect they vibrate loose, weird because everything was fine earlier then kaput no power whatsoever.

 

[FellowTraveler]

Today, again no power whatsoever so I dug into the cable ends shielding and oh crapola bad corrosion at crimped cable terminals, fixing it tomorrow.