Once transmission warms up it quits working. Any thoughts?

Hello, which engine is your F350 equipped with? You likely have the 4R100 automatic transmission with your F350. Depending on the engine your vehicle is equipped with, and if you have any vehicle modifications, many things can effect transmission performance. I would say, though, that if you have a temperature related transmission engagement or shifting problem, you likely have an internal hydraulic concern that is not adjustable or easily repaired. Certainly, perform a full fluid and filter change and see if that helps. Hello, you cannot "manually" turn off warning lights. And, warning lights being on - in themselves - are not reasons the vehicle will not start. Sounds like some diagnostic testing is in order to determine why your vehicle will not start, and unfortunately, you'll need some technical help from a shop near you. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops