Hi Sparks - I believed I had answered your question given the limited information provided.
If you posted up the exact year, model and engine type members may have a better idea and may be able to assist.
Relays can be used on many circuits on cars - indicators, wipers, and central locking just to name a few.
Do you have a particular problem with the car - if so post it up and someone may have found the solution in the past.
Sadly many wiring diagrams are copyright and are not allowed to be posted in this forum
Post away in the relevant section and see what responses you get - Good Luck and I hope you get things sorted