how to check the heater controls and check trans fluid

Kevvs, To diagnose the heater problem, you'll need to know how the heater system operates. There is probably a blend air door that controls the heat, so that will need to be checked. You really need a good repair manual if your going to be working on these types of problems, if you don't know how a system works you cannot diagnose it! For Jaguar I would look at http://bit.ly/Bentley_Repair_Manuals