My truck seems to start ok. Runs fine until I turn the headlights on. The truck completely dies and will crank but not start again unless I turn the headlights off. I can use the marker lights ok but not the headlights. I replaced the headlight switch last night and it all worked great again. Rode around for 20 min or so then parked. This morning leaving for work I started it up and turned the headlights on.....and it died again. Not sure where to go. Buddy said ignition relay may be bad and headlights pull the juice from it. Any ideas? Thank you.