Help! Lb7 electrical problem

[Vmyrhaug]

2003 silverado lb7.
Done complete engine and transmission swap from another lb7.
Is ready for first crank, but have big problem.
Tech2 cant find ecm or tcm.
No gear indication in display.
Fuel gauge on zero(tank is half)
Get code u1000 in transfer ecm.
After crank attemd, security light come on.
Battery have been disconnected several times.
Ground connection on both side of engine cleaned. Also engine too body connection.
Connectors on tcm and ecm have been connected several times.
Cant find any damagde on wiring.
Fuses is cheched.

Any suggesiton?

 

[mopar3]

You will need access to good wiring diagrams. Need to check for powers grounds and key power to ECM annd TCM.

 

[Vmyrhaug]

Does anybody have pinout for power and ground on ecm and tcm?

 

[Ron Nielson]

https://www.gmupfitter.com/pages/body-builder-manuals

 

[Vmyrhaug]

Updates. Ecmrpm fuse have no voltage. Edu rele not engaging. Short test, aligator clamp from engine ground too ecm case and it wakes up.
So is now chasing ecm ground problem. And alternator is not charging.

Is ecm ground connection left front of engine?
If so i know witch harness to split...

 

[Vmyrhaug]

New update. Fault found. Ecm ground wire is in same loom as starter signal. Was very bad closed too engine ground location on right side of engine. Will be fixed tomorrow. And also change alternator since it not working. Fault code on therminal. Wiring checked.