like i had posted a little while ago..my d5 light was dimmming and then when i floored it a little the light came to normal and its sounds like it could be the alternator.....i have another question about it because when i started my car the rpm goes up and down a little and the car dies and it did this a couple of times...and the only was it works is if i press on the pedal abd the rpm goes up or i just put it in drive....and then it works fine,......and then a few starts its good and then it happens again....can anyone help me........also i noticed that when i put my window down or up it seems like the chassis floor is giving it power and as soon as i let go of the switch its normal..thankss

 

if its got an alternator problem that means voltage is wrong everywhere and sensors are giving screwy info to the ecu
Fix the main problem and see what it solves
if alt bad, the battery is barely running the car and not getting recharged properly