The guest bathroom shower has a very minute amount of hot water coming out, just about none. While the sink runs hot water just fine. I took off the face to the faucet handle in the shower and checked to make sure the hot water was on, and it was. At this point I'm not sure which direction to head.

Let's get better acquainted. What's the brand name of your shower valve? How old is it? One handle or two knobs? Back to you, Tom

The brand is eljer and it has one handle. I'm not sure how old it is because its an apartment, but I've lived here a year and it hasn't been remodeled since.