Hello P Jamieson, I see that you pulled codes,If if an OBD2 scanner was used it won't pull codes in the BCM for communication problems.For this testing a factory level tool is needed. I did some more searching and found some failures that are similar to yours ,that replacing the ign. switch failed to correct. There have beer some with loose fuse connections and one had a corroded wire. I am sending some info and the wiring diagrams. You may want to print the diagrams out and piece together.You will see that fuses Ign O and IGN 1 feed power to the cluster.I hope this info helps you find the problem Jerry.
_____________________ ORIGINAL MESSAGE _____________________Below is my original help request Customer said some timeswhen they crank the truck that no lights in the instramentcluster are no gauges well work they cut the truck off andrestart it and every thing works. I don't think this isrelated to the transmission but the customer said one timethey started the truck and the motor was turning 4000 rpm andthe truck was barely moving like the transmission was slipingand the ckeck engine light came on they stoped cut it offrestarted and every thing was ok light off truck works finefor me. Pulled codes had P1860 Torque Conv Clutch PWM Sol CKT.P0740 Torque Conv Clutch Sol CKT. P0785 3-2 shift TimingSolenoid Problem. Any help would be appreciated Thanks GregMayfield ASE Master Cert.Everyone said ignition switch so I replaced it and thought Ihad it customer called and said it did it again truck willcrank and run but no gauges work and transmission want workright. He cut truck off and restarted and everything was OK. Ihave to be losing power some where but it is intermitant itwant do it when I have the truck. I don't have a informationsystem so I was wondering if someone could tell me were tostart checking at what connecter and what pins