your new tub spout with a diverter pullup simply blocks the flow. to
troubleshoot the shower head's vertical hidden pipe, remove shower
head and retest. if still misbehaving, remove the new spout and block
the spout's pipe with perhaps a 1/2" female iron pipe threaded cap, or
a short nipple with a sillcock. or a wet rag. turn on the handles and
turn off the water at the spout; this will send all the hot and cold
up the pipe to the open shower head. if the upper flow is great, try
it with a different shower head.

On Jan 27, 6:30 pm, "Ultraglide"
wrote:
I have a tub/shower combo. Just recently I noticed (it's the kids bathroom)
that only about half the water was coming out of the shower head and the
rest out of the bathtub faucet. I figured it was a diverter problem
(Waltec). I bought a new one and installed it and the problem remains. Is
there a trick to installing on of these things? I have done it before with
no problem.