Working on my sons 94 1500 4x4 5.7 with auto transmission. Started not wanting to shift out of first unless you let off the gas or manually shifted. He has changed the throttle position sensor, vehicle speed sensor, both shift solenoids, new fluid and filter and now it won’t shift out of first at all. No dash lights on, Speedo works . We’re not sure what to check next. Someone suggested taking the trans fuse out to see if it would start off in 3rd. We tried that and I’m pretty sure it did. He suggested the ecm is bad. Anyone had similar problems and could point us down the right path? Also, these problems literally started over night. No prior shifting problems or slipping etc. Thanks