[AC Fan speed switch]

Fan switch or blower motor is most likely broken on the 18 year old E-Series Van.  

[Anyone using Koni FSD shocks? E450 chassis]

I have been happy with Bilstein Shocks on my 2014 E-450 Winnebago Access 27 ft. Class C.   I just installed a Bilstein Steering Stablizer and that change seems to have reduced the little steering corrections while driving down the road.  If you are still in the market for shocks, I would go with the Bilsteins.....