Surprised to have had a bit of trouble finding a new heater motor when I could not get one working right & couldn't find another in my tons of saved 'junk'.
Napa did not even show one in their books. Took the old one in & the guy says, 'Oh, that's just a universal replacement motor.'
Ahh, yup, looked just like most others I have seen. But all the ones he came up with had a slightly shorter shaft. No good.
Went to Shucks. Dude looks it up. Special order, $65!
Got another guy there to take me in back & we opened up many boxes & found this. $48. Man, I know I have a free one here somewhere! 
Oh, well. Cut 7/8" off the end of the shaft, splice the stock connectors on the new motor's wires & use the old vent tube, good to go.
These fans are usually real easy to change out, but on this one unless you have an allen wrench that will reach at least 3 & 1/8" it will be tricky to get the fan off & on.
I didn't. : (
Before putting it back together I found this very rusty allen set in the old van. Shortened the 1/8" one & used a larger allen through the loop for leverage. I wanted that set screw reeal tight. About when I think I got it the loop on the 1/8' breaks off. Then the fan slides right off the shaft! WTF?!
Wish I'd found this little allen bit in my many hundreds of hand tools before I first took the fan off, would have saved me a lot of fumbling around & frustration. It is hard to get in there. Saved my butt after busting that 'looped' allen.
Still had to use that universal, the fins on the fan just did not line up straight with the set screw. Unusual.
New motor mounted up & fit just like the stocker. Now my heater/defroster really blows!
Oh, yeah, if you are having a problem with the blower motor switch, don't be afraid to take it apart. Nothing to it.
Clean it all up & put in some new dielectric grease, works smooth.
Oh- forgot to mention the big surprise that the motor was made in Canada instead of China like all the others we saw.
