Hi! everyone, ahve a question about using a DC power adaptor on cars & trucks. Our ford dealership uses a Dell Lattitude D620 w/ WXPPRO loaded & some software called integrated diognotic software to test cars & trks. My question is can it cause conflicts between the veh's pcm & laptop software when using the adaptor in the power point & not the cig. lighter? We have to take this laptop on testdrives to monitor pids on sensors & other componants & if were gone for a long period of time the laptop batt. gets weak & can't contiue using it. Was told by one of our other techs that it could cause problems when plugged into the cig. lighter & plugging into the diog. link connector under the dash. Something to do w/ voltage feedback causing the veh's pcm to fail. Don't know if this is true but would like to get some support on this issue please. Need to buy a DC adaptor as soon as possible. One batt is already going out for good & have a existing backup batt. The laptop has a unit called a VCM which plugs into the usb port in the laptop & then has another cable that plugs into the other end of the VCM (VEHICLE COMUNICATION MODULE) & goes to the the diog. link connector under the dash.