My tachometer has no reading at all, it might have happened after I was trying to find a blown fuse and was pulling them out, while the truck was running. I have switched out both the tach itself and the pickup sensor on the injection pump. I also followed the wires from the sensor to the firewall and they look fine. Any suggestions?

I tried to find something by searching the forum but most of them arenit about the 83-86 trucks