Water does not come out cold side of new faucet

You have a obstruction in cold side turn off both cold and hot water to faucet then disassemble cold side(take note of how you take apart it must go back correctly) slowly open cold water stop to see if you can dislodge obstruction(use a towel over cold water handle assembly to keep from water shooting everywhere).

probably have a kink on how water line feeding valve..if possible to cut drywall bhind tub valve and inspect pipe at bottom plate...moen faucets are equipped w/ anti scald device, pressure balanced (newer models) and this could cause cold water to overwhelm hot water...

do you have hot water elsewhere? if not, might be that your water heater is not heating.
if you do have hot water elsewhere, did you let the faucet run for a minute or 2.
did you have hot water before? is this a new house? new valve?
need a little more detail.
on posi temp valves, if there were no water coming out of the hot side of the valve, the valve will not operate.

Rust is usually a sign of galvanized pipe mixed with copper pipe incorrectly.Could be the pipe nipple used for the tub spout connection to the valve.You could change it to a brass nipple might be the problem

these valves can be adjusted by removing the handle and adjusting the white gear that regulates the hot and cold that come out, try going more to one way if it gets colder then go the other way.

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.

wow... I wish you hadn't gone thru the expense of replacing the faucet... it's perfectly good... your problem was the aerator, it unscrews at the tip of the water spout and had collected too much sediment which eventually blocked water flow. Often happens quickly after your water is shut off at the main valve. Aerators cost about 50 cents...

http://www.moen.com/contact.cfm?location=TopNavCustomerSupport

You will find a quicker answer and free parts for your bath room faucet at link above . I am sure it is the mixer valve assembly. If you are not a plumber I suggest a pro be called.

John

if the pressure is good with the head off then you can probably get a new head for it u shouldn't have to change the cartrige. it sounds like the head is clogged so plastic pieces in the head to help save water "water savers" it is hard to clean them i would try changing the head u should be able to find on for a moen, u buy for looks u buy it for life. take the old head with u when u go to buy a new one so they can match it up to the right one.if you can't find it and a lowes or home deptm try a plumbing supply house

call moen for new cartridge