When it is cold outside I have no dash or headlights

Let's start with the basics. When the issue is present, start by checking for power at the headlamp switch. This should be the red wire at the switch connector (see first attachment). From there, you can follow the circuit through the headlamp switch, to the beam selector switch and finally to the headlamp bulbs. The highlighted sections on both diagrams indicate where the circuit leads from the first page to the second. If you don't have power, you'll need to check the courtesy fuse to see if power is present there.

Let us know what you find!