I know this is weird, but my truck starts to buck and studder when I turn on my headlights. It won't studder when my running lights are on. Only when I turn on my headlights. I took it to Advance auto to have the battery and alternator checked. He told me the battery was bad and my alternator was good. I don't have trouble starting it. Sometimes it wants to quit while I am driving as well. I recently replaced my ICM but these problems started a week after I replaced it. Not sure if that would not be the problem, but I feel it is worth mentioning. I don't have the money for a battery right now, and I don't think that my led headlights that I have had for a year now, would pull enough current to effect anything. It does feel a bit sluggish, but I have no trouble going up hills. Just when those headlights come on.

 

I will check that as soon as I can. That never crossed my mind, thank you for thinking of it. I will message with the results later.

 

OK, Checked and unbolted, cleaned, and scraped shiny, the ground on left and right inside fender walls. Still no change. Check the plugs on my alternator also. Still studders when I turn the headlights on at around 1600 to 2000 rpm. She does not studder at idol speed.

 

No radio, no A/C, no other lights, except in cab, and the headlights are LED and I've had them for 6 plus months.

 

After pulling all of my hair out. I started looking at the battery and followed wires to no avail. Opened distributor cap cleaned all of the contacts. which were not bad at all and still no change. For poops and giggles, I swapped out the ICM. Low and behold!! that was the problem. Dam truck. I love it and hate it.