Just got this car from a individual..and was thrilled when A/C worked...but when the evening temps dropped, I turned up the temp....and no heat...tried all different positions etc...floor, dash, defrost, etc....but no heat. Plenty of coolant. Don't know how to do the self diagnostics...or what it may mean...
A/C works good, in all positions, however no heat when temp is increased... on 1994 Nissan 300ZX
by Aligator in Grove, OK on September 15, 2011
ANSWER by patrick mannion , September 15, 2011
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