It's easy to thread the belt the wrong way around the tensioner. If you do that, the belt won't have any tension. Don't ask how I know.
Double check the diagram (again).
If your new belt is the same as the old one, you're just threading it on wrong.
First truck -- 1929 Model A Ford pickup, restored from ground up. Wish I still had it!
99.5 F250 PSD Supercab LB 4x4, ZF-6 w/SB Con OFE, 3.73LS, Boost & pyro gauges, Swamps S175/146 injectors, DP 80 HP Econo PCM (classic version
), AIS, coolant filter w/"hokum" bracket,
regulated return, heated mirror mod, lighted cupholder, Marinco heater plug-in.
Hard or no-start? Check Here