My truck would start with starting fluid I changed my fuel pump with the battery connected and now it will not start even with starting fluid did I trip a safty relay or somthing I dont have 200 caricters to say to fill this up
You left out a lot of important information. Which engine do you have? What is the symptom? "Doesn't start" is as informative as "I'm in pain".
Does the starter crank the engine at the proper speed? Do you have a diesel or gas engine? Have you checked for spark and fuel pressure? What about diagnostic fault codes. Has anyone checked for those?