The headlights work as normal but the driving lights don't come on.
Truck is a 99 2500 with the cummins of course.
First I checked the bulbs, okay.
Second I checked the wire for power with switch on, has power on both sides of the pigtail. Do they ground to run and if so is there a relay.
Ran out of time so tommorow I should check wire for power and ground with switch off.
Thanks for any help.
Chris

 

IIRC they are ground switched. So make sure and check the grounds. Obviously the switch could have failed or the multifunction switch could be the culprit as well since it switches them on or off depending on low or high beams being used.

 

One day last week my daytime running lights wouldn't come on. Turns out when I used the parking brake that day, when I pulled the release the pedal only came 99% of the way back up. I pulled the brake release and lifted the pedal all the way up with my foot. Problem solved, daytime running lights came back on.

It was the middle of the afternoon when I noticed. The lights were off in the garage when I pulled in or I wouldn't have noticed. The brake indicator in the dash did not indicate a problem.

 

I got sidetracked today, replaced a few tail light bulbs and the licence plate wire harness. Put on the stock mudflaps and re installed the liner on the tailgate.
Might be able to get back to the driving lights tommorow.
Thanks Chris

 

Fuse or switch most likely. The headlight switches generate a ton of heat on these trucks and are prone to fail.

Fuses are a lot cheaper, hopin that is what it is......