We have a Delta 2-handle faucet. All of a sudden, it started dripping. We
found out that the cold water side was the culprit. We replaced the Stem
Unit (RP1740) on the cold water side. The faucet still dripped. Then we
put the NEW stem unit on the HOT water side and put the stem unit from the
hot water side on the COLD water side and the cold water side still drips.
Apparently the stem unit was not the problem.

We're confused as to what to do next. Right now, we've just turned off the
water to the cold side to stop the dripping.

Does anyone know what could be causing the drip?

Thanks in advance,
Debbie