98 silverado trans prob

i found another prob just like mine wont shift out of 3rd and no cluster. but the fuse in slot 20 is only giving me 5 volts with the ignition in the on pos. and .85 volts with the truck running also is jumping erratic up and down. what should the reading be ? could this just be a bad ignition switch. also the codes coming up are all the solenoids in the trans and all the 02 sensors. is this cause its not getting power. but now some times when i start to drive the cluster starts to work but the speed is not right. and if i shift down to 2nd the cluster stops working and the check gauge lite comes on.

Could be the ignition switch, check voltage in the underhood fuse box on fuses IGN-A and IGN-B or IGN-1 and IGN-2- if those are low check battery connections and grounding, if they have 12v, its the ignition switch