Ford 6.8 serpentine belt

It was the ford as I stated. It was traveling friends. Called Good Sams and first call ended up worthless. Called on Monday and finally got a service call out to repair it. Costs over $600. I think the guy took a nap under the motorhome. I think I could have changed it in 15 min max if I could have gotten the belt. Thanks for the one answer I recieved for my question. I should have stated my problem in a clearer manner.

Jeepers92....If you had your RV life to live over again at what time/mileage intervals would you replace your belts and hoses?

I do mine about every 4 to 5 years and have been told that's excessive.