If no heat, where does the temperature gauge read when you are on the freeway, if it reads well less than half way perhaps the thermostat is stuck open. See that the coolant hoses to the heater core are not bypassed, may indicate a leaking heater core. There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online