My shower faucet is a single knob that rotates to turn water on and also control temperature (Moen). The problem is that there seems to be no cold water mixing any longer. Even when the faucet is turned a little, I am only getting scalding hot water. I am not having this issue with my other shower and I have cold water coming through all other faucets in the house. I suspect it may be the Moen cartridge, but I don't know enough about how they work to know for sure. Has anyone had this issue with Moen faucets? Was it the cartridge or something else? Any feedback is appreciated.

The cartridge is installed backwards. It is a moen positemp. You got to turn the water off, pull the clip, pull the cartridge half way out, rotate 180 degrees, and push back in and replace clip and handle. Don't break the tabs on the cartridge as you pull it out, the cartridge is almost forty bucks.

Or the cartridge has gone bad