I need to change heater core i need diagram - 1999 Ford Expedition

All depends on what you are working on, but it is usually the one from the pump.

Heater core replacement is delicate and it is very easy to damage hard to get parts, including the core itself. This job may be best for a shop to handle. The heater core is located in the heater box, follow the heater hoses from the engine to the passenger side firewall area...

from autozone.com:

1992-96 Models

See Figures 1, 2 and 3

1. Disconnect the negative battery cable.
2. From under the dash, remove the heater protector from the front of the A/C and heater unit. It is attached by two clips.

Fig. Fig. 1: The heater protector is a panel attached to the front of the unit

1. Unscrew and unclasp the heater core. Disconnect the heater pipes.

Fig. Fig. 2: There are three screws holding the pipe clamps

1. Pull the core out of the vehicle.

Fig. Fig. 3: Slide the core out in this direction from the unit


To install:

1. Place the core into the A/C and heater unit.
2. Connect the heater pipes.
3. Install the 3 clamps and screws to secure the unit.
4. Install the heater protector.

9. Remove radiator cap, start car, refill system, allow car to reach normal temp with thermostat open and coolant flowing in radiator. open any bleed ports on engine to release trapped air. top off radiator and close cap.

Check the fuses. My heater went out so I changed the fuses and it works perfectly now!

The only thing to do is get a diagram from the MAZDA dealer parts dept. "A few parts fell out" is way to vague to help you.

Hi:
I have changed out a heater core on a Blazer like yours and while it isn't extremely difficult, it is quite a job, as you need to remove the dash to do so.

If you need some guidance, I would suggest that you spend about $20 and get a subscription to :
www.alldatadiy.com

It helped me on all of the cars that I had, and has step by step instructions, as well as printable diagrams and pictures.

I believe all your major auto parts stores have web sites with instructions and diagrams to help you with your project.

there is no easy way to change out a heater core...you have to take the bottom part of the dash loose and that takes some doing. once you get the bottom of the dash apart you will see the heater core.then you have to go under the hood and unhook both water lines that run to it, you should then be able to pull the heater core out and install the new one

need to change cooling lines for 2003 kia sedona,need diagrams

The automotive repair manuels that you can buy at the major part stores such as Autozone, Advance or ORiley's do a good job of describing how the heater core is removed. Most heater cores come out from under the dash, while a rare few are removed from the firewall.

One wonders why you are changing the heater core. Are you getting steam on the inside of your windshield? Usually the best indication your heater core is leaking, or are you getting no heat? In which case it make be duct doors.

Bill