We installed a Delta diverting valve and cartridge for a hand held shower head.Put in a separate valve for the main shower head, however when we turn the water on we can not shut the water off at the diverting valve. The diverting valve has hot and cold water running to it as well as the other valve. Is this correct? Also having a problem with no hot water and low pressure in the upstairs shower.

Are you calling your shower valve a diverter valve? Any diverting valve that I know of has two, three or more ports and is used to direct water as desired.

If I am not mistaken, a three port diverter valve was needed here where the inlet to the diverter comes from the shower valve itself (one pipe from the shower outlet of the shower valve), the other port gets piped to the regular shower head and the other port gets piped to the hand-held shower head.

No hot or cold should go to the diverter valve, just the outlet from the shower valve itself... see image?

We can discuss the upstairs shower issue later.

Let me know if I misunderstood you, OK?

Mark