An ex-con stole an idling SUV in the West Village, and cops tracked him down with an iPad that was left in the car, police sources said.

Herman Johnson, 55, was indicted on Monday for the May 13 theft where he drove off in a 2013 Jeep Wrangler that was left running on Greenwich Avenue while the car’s owner ran into a store, cops said.

Police, who knew his location from the iPad tracker, pulled up in front of the vehicle, according to a court complaint.

He then rammed head-on into the cop car before backing into two other vehicles, sources said.

Johnson was held without bail, sources said.