Daytime running light ?

My brother has a 2012 2500 diesel 6 speed, when he has his light sw in auto and it is dark out, only his drl come on, he can tell when he turns lights on manually they get brighter also when during the day, sw in auto he turns blinker on, whichever side is on the headlight on that side goes out. My truck does none of this, it is a 2012 2500 Hemi auto, does or can anyone check their truck to see what it does? He has had it to dealer twice,they have replaced some switches and also when in auto his dash lights are not on during the day. Thanks

his lights are functioning correctly, for a truck that is set to have DRLs on.

But shouldnt headlights come on fully after dark not drl's? And why would diesels work that way and not the Hemi's?

the dim issue does sound odd.........not sure on that one, but the difference in engine shouldn't matter.

I had my DRLs turned on when I bought my 2012 Express. My headlights are always set on AUTO. The DRLs come on in daylight when I put the truck in gear. When it gets dark the headlights come on by themselves. There is no light on the dash to let you know they came on but I set the foglights on and then the symbol for the foglights lights up whenever the DRLs switch to regular headlight mode.

I had a previous 2007 diesel with a manual trans and had the same dealer activate the DRLs on that truck too. It would bring on the DRLs when you released the parking brake. On that truck there was no automatic headlight function so I had to turn the headlights on manually when it got dark.

It sounds like your auto lights aren't working but I don't think all the trucks have that feature. If you have a switch position for auto then you'd think the feature was there though.