Can't locate the headlight relay

I was wondering if anyone could help me locate where the retractable headlamp relay is on a 1988 Dodge Daytona Shelby Z Turbo. The lights will not come up or they do when they feel like it. I can be driving at night and they will just go out and will not come back up...could anyone please give me any ideas of how to fix this and find the headlamp relay.
Tracy Fair