No Hot water coming out when single handle on hot water side.Cold water comes out fine. Water in the lines leading to the taps, but no hot water coming out. This is a bathroom faucet Moen single handle.

Who ever hooked the pipes up to the tap they put the cold pipe on the hot side of tap. Same the other side. You need to change the pipes to opposite side of tap.

Tap and lines on hot side could be plugged.

some new faucets come with there on supply lines when you tighten one will twist at the top near the faucet look under the sink to see if this has happened. i've had it happen not long ago

Question is not 100% clear.
System is not described.
Hot water will come out of cold tap of you have recirculation system.
Without a direct return line, the cold water pipe is filled with hot water.
So hot water is available immediately, but you wait for cold water when recirculation system is on.
http://waterheatertimer.org/Water-heater-recirculation-system.html

If you install a direct return line, then cold water line is not used for recirculation, and cold water is available immediately.
Another possible solution, depending on problem, is to use timer instead of thermostat to control recirculation system. Using the timer means hot water is inside the cold pipe only when the timed operation is running. This will let you have immediate cold water.
Link above has information how to choose timer vrs thermostat.

If cold water never arrives no matter how long you run the hot tap, then check-valve on recirculation system is not working, or you have crossover on single-handled faucet, or both.
http://waterheatertimer.org/Crossover.html

Best solution is to remove the circulation-system crossover located under sink and see if problem is solved.
After removing crossover piece, try hot water tap.
Another way to check if this is the problem: Turn off cold water shut-off located above water heater. No need to turn off power or gas to water heater. Now, no water should flow when you turn on hot water tap because hot is turned off.
Open hot water side of double handled faucet. If water still comes out the hot side, then crossover is the problem.

After removing Taco crossover, you can still have the problem if a single handled faucet has the same type of crossover issue.
Repeat test to see if water comes out of hot side when water to water heater is shut off.
If water still comes out of hot side, then put ear against each single handled faucet and see which one has sound of moving water. That will narrow down the suspects.

Hot water line connected to left side of faucet? Did you replace tap set, or just cartridge? Cartridge may be out 180 degrees.

Replace the cartridge

You can try to rotate the first plastic ring to the left of center a few teeth, this will let the handle advance alittle more to the hot side.

Dis-assemble the faucet to get to the valve. The handle comes off and you access the valve from the top, usually by removing a screw on ring.

You will robably find contamination in the hot side of the valve.

You can find instructions on the Moen website.

The plumbers screwed up when they installed your showers. There are two connections on each shower. one for hot and one for cold. they connected the two hot water lines together with a T fitting and then ran a line to the main hot water line and tied it in. Then they connected the two cold water fittings with a T and ran that line to the main hot water line and tied it in there instead of into a cold water line like they were suppose to. This is the only possible logical solution to this problem. They tied your cold water connections to both showers into a hot water line instead of a cold water line.