I have a new sink in my laundry room that has cold and hot water supply lines going to it. I have verified that both of the shutoff valves are working correctly and water is coming out when they are turned on. But when the supply lines are hooked to the faucet only the hot is working. I've tried 2 different supply lines and 2 different faucets and get the same behavior. I'm at a loss as to what the issue might be. Any recommendations on things to try?
According to your tests, the supply line is certainly the culprit. Are these new replacements? If not, do replace them with new. If so, then one is faulty. Either way, sounds like the answer is the line between the valve and the faucet.