Heater hose location - 1999 Ford Expedition

I couldn't find a heater hose diagram specific to the 1999 Chevrolet Venture with rear heat and air, but I can give you the general location of the heater hoses and how to identify which ones go to the rear heat. The heater hoses on a 1999 Chevy Venture are located on the passenger side of the engine compartment. There are two heater hoses, one that is hot and one that is cold. The hot heater hose will be connected to the heater core, which is located under the dashboard. The cold heater hose will be connected to the engine. To identify which heater hose goes to the rear heat, you can look for the hose that is connected to the heater core outlet that is labeled "Rear Heat." The other heater hose will be connected to the heater core outlet that is labeled "Heating Core Inlet." Once you have identified the heater hoses that go to the rear heat, you can reconnect them to the heater core. Be sure to use new clamps when you reconnect the hoses. Here are the steps on how to replace the heater hoses on a 1999 Chevy Venture with rear heat and air: Disconnect the negative battery cable. Drain the coolant from the radiator. Remove the heater hoses from the engine and heater core. Install the new heater hoses. Fill the cooling system with coolant. Reconnect the battery cable. Start the engine and check for leaks.

If it has a AC you have to pump down the AC remove the entire heater and AC unit so you can disconect AC lines and heater hoses ,you have to drop the steering column and remove the glove box, its a big job I would buy a manual so you know what all you have to disconect.

Sounds like the air blend door is not opening to let heat in.

Engine coolant is provided to the heater system by two 16 mm (5/8 inch inside diameter) heater hoses. With the engine idling at normal running temperature, set the heater-A/C controls as follows. Temperature control to full Heat, Mode control to Floor, Blower control to the highest speed setting. Using a test thermometer, check the air temperature coming from the center floor outlets and compare this reading to the Temperature Reference table.

If the floor outlet air temperature is insufficient, check that the cooling system is operating to specifications. Both heater hoses should be HOT to the touch (the coolant return hose should be slightly cooler than the supply hose). If the coolant return hose is much cooler than the supply hose, locate and repair the engine coolant flow obstruction in heater system.

POSSIBLE LOCATIONS OR CAUSE OF OBSTRUCTED COOLANT FLOW

• Pinched or kinked heater hoses.
• Improper heater hose routing.
• Plugged heater hoses or supply and return ports at cooling system connections.
• Plugged heater core.
• Air locked heater core.
• Restrictor in backwards

If coolant flow is verified and the heater floor outlet temperature is insufficient, a mechanical problem may exist.

POSSIBLE LOCATION OR CAUSE OF INSUFFICIENT HEAT

• Obstructed cowl air intake.
• Obstructed heater system outlets.
• Blend-air door not functioning properly.

TEMPERATURE CONTROL
If heater floor outlet temperature cannot be adjusted with the heater-A/C control temperature control lever, one of the following could require service:

• Blend-air door binding.
• Faulty blend-air door motor.
• Improper engine coolant temperature.
• Faulty heater-A/C control.

trace the upper radiater hose back to engine. Where this hose connects to engine is called the "thermostat housing" thermostats are usually located under these or their extensions. The first thing I would check when I have a "low heat" situation, is the connections where the heater hoses connect to the engine for rust and corrosion, or clogged heater hoses or heater core cloggs.

The heater hose go from the engine through the engine firewall, there are two of them, one is slightly larger than the other

The best way to locate a heater core hose is to determine where the heater core is located. Many vehicles have the heater core inside the dash. Other vehicles, usually larger vans and trucks, will have a heater core box inside the engine compartment. Once you have determined where the heater core is located in your vehicle, that will allow you to easily locate a heater core hose. If the heater core is inside the dash, you'll need to examine the firewall for the hoses. If it is in a heater box, you'll need to look around the engine compartment for the box.




Heater cores located inside dashes can be very difficult and time consuming to replace. Depending on the layout of your engine compartment, it can also be difficult to locate a heater core hose. If there is very little clearance between the engine and the firewall, you may have difficulty finding the hoses. You might need to use a flashlight to look from the underside in some cases. You will typically be able to identify the heater hoses where they enter the firewall by looking for two two small diameter hoses that protrude into the engine compartment. You can then trace those hoses to their other ends, where they will typically connect to a thermostat housing, the radiator, or a t-connector.


Hope this helps.


know more about your car

1. Drain the engine coolant.
   
2. Reposition the outlet heater hose clamp at the heater core.
3. Remove the outlet heater hose from the heater core.
4. Reposition the inlet heater hose clamp at the heater core.
5. Remove the inlet heater hose from the heater core.
6. Remove the screws that retain the cover to the heater case assembly. This is located underneath the dash on the passenger side.
   
7. Remove the straps that retain the heater core to the heater case assembly.
8. Remove the heater core from the vehicle.

is it actually on the engine? I ask because you say it is to the passenger side and just behind the engine, that makes me think it is a heater hose, the heater hoses go from the water pump to the heater core which is located on the passenger side, the difference between heater hoses and radiator hoses is the size and of course location, heater hoses are generally about 1/2 inch to 1 inch, with radiator hoses being between 1 3/4 and 3 inches

Usually you open the hood. By the firewall you will see 2-hoses almost side-by-side that go in the middle of the firewall. Those two are the heater hoses.