Park lights

have a strange issue happening with my truck.Its a 2011 GMC Sierra with the 4.8,4x4.At night when I unlock my doors the truck will turn on the park lights outside no problem but when I start it up I usually have no parks outside.All the dash lights work fine,headlights are fine.I usually leave the headlight switch to the auto setting but even if I switch to the parks only or headlights they still won't come on.They all work with illuminated entry or door lock just not for driving.All the lights inside that come on with park lights work fine.Sometimes they do come on but more often they don't.Any ideas as to where I could look for this problem?Anybody have a schematic of the headlight circuit?

Multifunction switch is a good culprit to look at. They are a common problem on many various GMs.

wasn't the switch,I had the original switch left over from when I converted her to driving lights but I did find the issue.It was the park light relay under the hood in the fuse box.