It won't lock on to the new crankshaft sensor

Hooboy. See if it will still lock onto the old sensor, if it will then there's something wrong with your new one. If it won't lock on the old one, make sure the tab is fully pushed in, sometimes they won't seat if they're not fully locked before insertion. Use a channellocks if necessary to pinch it all the way down. Try some WD40 on it also, they can jam from crud in the mechanism. If none of that works and you can't find a new pigtail, I think I have one or two in our collection at the shop.