Stop in for a cup of coffee

Has been a cold day, got one oil change done, and did get avalanche serviced as well. Tried troubleshooting the evap purge solenoid fault,to no avail. I made a jumper and tested the circuit,9 ohms resistance from ecu to solenoid and back. I call it pretty good. Plugged it back in and reconnected battery and its behaving. I can assume its pinched against another wire,and when it gets wet, the circuit bridges and causes a fault.