I recently purchased and installed a new diverter for my 3 valve shower setup. However, when I turn the diverter to shower I get very little water pressure to the shower head and no water coming from the faucet. Is there any trick to properly installing the new diverter to allow for full water flow to the showerhead? All parts are brand new and an exact replica of old diverter.

Was the cartridge in place when you bought it or did you install it? Sounds like it may be rotated wrong.