I'm in the process of replacing the serpentine belt on my '89 E250 with a 5.8 351 engine, I am replacing it with the same size 94 1/2" belt but can't get proper tension. I no longer have a diagram on the vehicle & have sourced a diagram both from the auto parts store & a Dayco fitment book, installing it according to this diagram does not give proper tension, this engine has Alternator, Air pump,CS pulley, tensioner pulley, P/S pump, & AC compressor, no idler pulley, any suggestions appreciated

 

2 things, are you sure the tensioner is working it's full range and what is a CS pulley? Do you mean the water pump ?

 

tensioner would appear to be OK, I compared it to a new 1 & it seems fine

 

There are a few variations. Suggest you type in your search browser, "1989 ford belt routing diagrams". Just about all the variations are shown there.

 

This may help someone with this problem... Found it online...

 

any one of those pulleys that have a smooth surface on the outside means that the belt must have the smooth side of it on the pulley, the pulleys that are smooth turn opposite the the pulleys with the grooved pulleys. the engine rotates clockwise and the water pump turns counter clockwise as does the tensioner those should be the only two pulleys that are smooth. another thing that could cause a loose belt is that the belt is too long and the engine may have been replaced or the pulleys are the wrong size. take that belt back to the parts store and replace it with one that is one inch shorter than the one you have