You need basic electrical troubleshooting skills. There are so many possibilities that I wouldn't know where to start without having the car in front of me to check-out. It could be any of several problems, bulbs, switch, wire, grounding connectors. You've posted a question that can't be answered with the information provided.
Dodge Rams are not equipped with Daytime running lights.. Although what you can do is turn on the parking lights and select just your fog lights (if equipped) otherwise to have running lights you will need to turn on your headlights. It's not a huge advantage to have running lights, because when the climates come that you need to turn on the headlights anyways, they aren't necessary.
It can be the dimmer switch. It needs to be checked out./ A test light will check for voltage.
It is probably the running lights that are working and the regular headlights aren't working because of the switch or wiring. TAke it to a garage.
headlights
The headlights and the tail lights may not be working on the 1981 El Camino because of a mechanical breakdown.
Fuse for parking lights probably blown.
What year is the vehicle? Did you check the fuse?
check the fuses - there is no fuse for the headlights.
Well, the daytime running lights are on whenever the car is running and in gear. They're off when you have the headlights on. So, your service light Doesn't come on when the headlights are on?? If you switch the headlights between on and off (with the car running and in gear) does the service light follow?
my headlights and dash lights stopped working on my 2007 yamati strada RX150
no
Yes, they did.