You have a '95 mercury vill 30l v-6 you think you need a new heater core how much and how do you install it where do you find it under the engine what does it look like?

If you're asking all these questions, you're better off taking it to a mechanic and have them check it for you. The heater core is located under the dash, bolted to the firewall. It's a complicated and very frustrating procedure to change one. If it's leaking, you'd notice the carpet was wet and yuou'd smell coolant inside the car. If it just doesn't blow heat from the heater, it might just be clogged, and the entire cooling system needs backflushed. You can check this by warming up the engine until the radiator hose is warm/hot to the touch, and then locate the two heater hoses that go to the firewall from the engine. One is an inlet, the other is a return hose. If only one of them is warm, then the heater core is clogged, if both are warm, the your problem is something else. The climate control system utilizes vacuum operated "doors" or "flaps" to direct air to the passenger compartment. Check that all of them are functioning properly. If you have an electronic climate control system, it could be faulty.