I pulled truck in the garage to change brake light switch. When I pulled it out the next day it wouldn't shift out of low gear. I noticed also that the speedometer wasn't working. I thought the trans had went out, went to my trans man an he laughed. He said if the speedometer doesn't work, it won't shift. I can't see that I've unplugged anything, does anyone have any idea what could be wrong? I changed the speed sensor in the trans today and it didn't fix anything. I have a 4L60E. I've chased wires, cleaned terminals, everything I can think of? It has to be something simple. You can pull the trans fuse out, and the truck will take off in high gear and run normal speed, it just won't take off. As soon as you put the fuse back it, it won't shift. I don't think the trans is out because it will pull as normal once you get it going with the fuse out. Please help, I'm pulling my hair out. Thanks Brandon.