I'm having an issue with the check engine light and the battery light coming on everytime I start the vehicle...and they will stay on untill I rev up the engine or start driving it to get the rpm up...the dash lights and headlights are dim until the rpm gets up and the battery and check engine lights go off...been doing it about 2 years and I just had the battery starter and alternator checked 2 days ago and they all tested good....any help would be appreciated