Shower body three way diverter problem, no water to one port

Can you take a picture and post what you have?

follow this steps and fix it. God bless you
If a faucet leaks, replace seals and gaskets .
If a shower head leaks, create a better seal or replace seals .
If a sillcock wears out, replace the washers .
If a compression faucet drips from the spout, replace the washer and/or the seat .
If a faucet leaks from the handle, replace O-ring(s), replace the packing washer, tighten the packing nut, or replace worn packing, depending on the valve type .
If a ball or cartridge faucet leaks from the collar, replace worn O-rings .
If a disk faucet leaks around the base or has reduced flow, replace cracked or pitted disk assembly or worn inlet seals .
If there is water under the sink, tighten the faucet-set locknuts under the sink. You also can replace putty or a gasket, replace a worn faucet, or replace leaky supply tubes .
If the aerator leaks around the edge, replace the washer in the aerator .
If the spray hose leaks or has reduced flow, replace the O-ring on the diverter valve, replace a worn washer at the base of the spray head, or clean the diverter valve and spray head .

valve is bleeding by remove and check the condition of cartrige look for wear or dirt

yep replace the unit the plumbing will be ok for a new unit, with a setup lie that whoever installed it hopefully was smart to put shut off valves behind the wall or you will have to turn off h20o supply and replace and solder caps on the rest easier to change out to new

Diverter valves don't regulate the temp at all they are used with a standard shower valve that regulates the temp and the diverter selects the shower head/body spray/Rain head or whatever configuration you have. This valve can't be used on it's own.

Each function needs its own control valve .

I had the same problem. I discovered that an O ring was missing (or I lost it without noticing) from a new diverter that I installed. Just got an O ring that fits on the threaded part of the collar where it meets the pipe. Worked fine. Amazing how a little plastic piece could make such a difference.

Easy way go to your local plumber or call...maybe take a pic.

Remove hot/cold button in handle, remove screw/pull off handle. Remove the two screws in the wall plate/remove plate. Use a wrench to remove the diverter assembly. Get new diverter assy and reinstall eveything. You don't need to turn off the water.

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If I understand you correctly your not getting any water out of your shower head .It could be your shower head is clogged,
or your diverter is bad. Diverter takes the water up to the shower head.