I have a two-handle tub&shower Delta faucet-diverter. There is only a trickle coming out when the cold-water handle is turned on and regular amount of water when the hot-water handle is turned on. I removed the cold-water stem turned on the water and there was a strong supply of cold water. As I concluded that the stoppage is between the cold-water handle and the spout I caped the shower removed the spout trim and blew air (from a small compressor) in the spout pipe. Very little air came out at the handle. I put it all back together planning to cut the wall and replace the faucet next week. Any ideas out there short of going into the wall and replacing the whole thing. Unfortunately the main cut off gate valve leaks quite a bit when closed so it needs to be replaced if I am going to solder.
A common problem with this valve is the balancing spool sticks.This part is located on the cold water inlet before the cartridge.You can purchase a new one or clean and grease the old one.Buying a new one first would be your best choice.