Cold water handle on my American Standard cold water control just spins around with out turning on the water

mixing valve and ceramic washers are defective. American Standard is not what it used to be. Parts are substandard and imported from china. Get yourself a Glacier Bay, and contact American Standard and demand your money back or a credit.

My best advice
is to believe everything you just experienced...
(Perhaps an UNSEEN flaw in the "MONOBLOCK")

Buy the replacement faucet... shop around:
I spotted it on eBay... (number not close...)
((but still reasonably priced)).

AMAZON
American Standard 1480 101 002 Seva Single Control Lavatory Faucet with...

Also went to eFaucets (but their site was stunned
(normally GOOD resource... ))
http://efaucets.com/

eBay (concierge... buyer protected... FREE ship'n)
American Standard 1480 150 002 Seva Monoblock Single Lever Handle Lavatory...

Save the old one (parts)and DIAGNOSE
it in your SPARE TIME...

Hope this helps

Carnac the Magnificent

see here for parts. also avalible at ace hardware https://www.americanstandard-us.com/parts-support/parts/faucet-parts/bath-shower-faucet-parts?page=1&plimit=21

The water lines have been connected incorrectly. Reverse the connections under the sink.

Check the aerator and see if it is getting plug up.

Your valve has an anti-scald feature which automatically adjusts the water temp if cold water is diverted to another location, e.g., a flushed toilet, washing machine filling, etc. Most valves have an adjustment screw to allow you to set the temp. Since each manufacturer is different you'll need the manual or contact the manufacturers support. BTW, these anti-scald valves are being added to building codes in many parts of the U.S.

Remove the handle,and all the trim rings,and the cartridge cover. take a flat head screwdriver and use it to lift
up the red ring behind everything, this is the hot limit safety stop,
this just stops the handle from turning to full hot.

Once you have the red ring lifted up, notice the numbers and the pointer
on the ring, numbers are on the fixture,

O= hottest 7=cold

See what the ring pointer is set to now, and move it half, before you put this back together, just set the handle on the unit and run the water to see if its to hot or not enough. Once you have found what is the best setting, then replace all covers and trim, handle.

there should be a little cap covering a allen srew in the front or back of the handle it sometimes looks like the hot or cold sign or chrome pop that off and loosen the screw and pull off the handle there should be a nut loosen that and pull up the cartridge you might be able to find one at home depot be sure to turn the water supply off

When you installed the new tub faucet you probably turned off the water to that faucet of even the whole house. IF IT IS AN OLDER HOUSE, TURNING THE WATER OFF AND BACK ON CAN LOOSEN SOME DEBRIS IN THE WATER LINES THAT CAN FIND THEIR WAY TO YOUR NEW FAUCET. If there is a screen at the end of the water outlet it can be clogged with gunk. Uncrew the screen on the water outlet and clean. You may also want to flush out the hot and cold outlets by turning the water off, removing the cartigages and slowly let water flush them out. Then reassemble. Also when you have the tub handles out you can turn the hot and cold supply valves off and on a few times to loosen more debris if it exsists........Joe

you didnt mention which side hot or cold?
it sounds like its scaled up & the o ring has dried out so it could be a case of replacing o ring & regreasing. ifits when you turn either hot or cold & its stiff then a replacement cartridge will required

Kindly

Richie