Erratic idle when blower motor runs
I have a 2003 Ranger Edge, 4.0 engine. when i'm stopped but in gear, anytime the blower fan is running (on heat, ac, or defrost) i hear a "click" then the engine/rpm's bogg down and feels like the engine is going to stall, and then it recovers. and it does that every 10 seconds or so. the headlites, etc go dim for a second everytime it boggs down too. but it will only do this IF the transmission is in gear AND the blower is running. it won't do it idling in Park, but if i shift thru the gears to Park, then it does it right when the selector hits Park. thought maybe the alternator was bad, but i checked it and it's good. so is the battery and starter. also, i hooked up the OBD II code scanner and i get no codes. could this be a ground problem somewhere???