Check Engine-Torque Converter Errors HELP? 97 GMC K1500

1997 GMC K1500 5.7 M30 Trans
I just put in a new engine one month ago, (crate).

My gages stop working RPMs, Speedo, Fuel, Oil, Water, Volts, and shift indicator. Before this I was getting the Check Gages light flickering. However sometimes the gages do work normal and everything seems fine.
When the gages do go off and stop working the check engine light turns on and the truck runs just like the transmission is slipping.

Error codes 6 of 9
P0740 Torque Converter Clutch Solenoid Circuit /Open
p0753 Shift Solenoid A Electrical
P0758 Shift Solenoid B Electrical
p0785 Shift/Timing Solenoid Malfunction
p01860 Torque Converter Clutch Pulse width Malfunction circuit
p0740 Torque Converter Clutch circuit open

Just wondering what electrical item is failing?
Can't be a fuse due to when the gages are working the trans seems 100%, but when the gages go out the trans seems to slip in forward gears only.

Any help on this I would GREATLY appreciate.

Repl. the ign switch, check the trans fuse, make sure the main plug on the trans is fully seated.

Repl. the ign switch, check the trans fuse, make sure the main plug on the trans is fully seated.

Thank you can do fuses all OK in cab and under hood!
I will go under. Thanks again!