Heater System Ford Econoline E350

DESCRIPTION

"E" series vans are available with an auxiliary (rear) heater in addition to the standard (front) heater system. Heater systems are of a blend-air design, consisting of control panel, heater blower assembly and plenum assembly.

Front heater blower assembly is located in engine compartment and contains blower motor, fan wheel and blower resistor. The front plenum assembly is located under the instrument panel and contains heater core, floor/defroster door, panel/defrost door and temperature blend door.

Rear heater assembly is mounted in left rear corner of cargo area. Blower and heater assemblies are combined into a single unit containing heater core, blower motor, blower resistor and ducts.

Control panel is mounted in dashboard and contains function control lever, temperature control lever and blower control switch. Rear heater equipped vehicles have 2 blower switches which work independently of one another.

BLOWER SWITCHES

Control panel mounted front and rear blower switches have LO (low), medium low, medium high and HI speed positions. Auxiliary switch also has an OFF position. When function selector lever is in OFF position, blower speed switch is open. (Scheme 2)

FUNCTION SELECTOR LEVER

The function selector lever can be placed in OFF, VENT, FLOOR, DEF/FLR and DEF positions. The position of the function selector lever determines whether function damper doors are open, partially open or closed. Function damper doors direct airflow to the selected outlets. The 3 function vacuum motors and doors are outside/recirculation, panel/defrost and panel/floor.

OFF

In OFF mode, full vacuum is applied to the outside/recirculation and floor/defroster vacuum motors. Vacuum is not applied to the panel/defroster vacuum motor. Blower motor is off. Temperature can be adjusted as desired. Recirculated air is directed to floor outlets.

VENT

In VENT mode, outside air is allowed into system. Vacuum is not applied to outside/recirculation vacuum motor. Recirculation air is shut off by the outside/recirculation mode door. Full vacuum is applied to panel/defroster and floor/defroster vacuum motor. Airflow is directed to panel outlets. Blower motor speed and temperature can be adjusted to desired settings.

FLOOR

In FLOOR mode, outside air is allowed through system. Vacuum is not applied to the outside/recirculation vacuum motor. Recirculated air is blocked off. Full vacuum is applied to floor/defroster vacuum motor. Vacuum is not applied to panel/defroster vacuum motor. Airflow is routed to floor outlets. Blower motor speed and temperature can be adjusted to desired settings.

DEF/FLR

In DEF/FLR (defrost/floor) mode, outside air is allowed into system. Vacuum is not applied to outside/recirculation and panel/defrost vacuum motors. The floor/defrost vacuum motor has partial vacuum allowing equal outlet airflow. Blower motor speed and temperature can be adjusted to desired settings.

DEF

In DEF (defrost) mode, outside air is routed through system and out defroster outlets. Vacuum is not applied to outside/recirculation, floor/panel and panel/defrost vacuum motors. Blower motor speed and temperature can be adjusted to desired settings.

TEMPERATURE SELECTOR LEVER

Temperature selector lever mechanically operates a cable to adjust temperature blend door in plenum assembly. When temperature selector lever is in COOL position, blend-air door closes airflow to heater core. When lever is in WARM position, air is directed through the heater core. In intermediate positions, heated air is blended with cooler incoming air to achieve desired temperature.

TEMPERATURE CONTROL CABLE ADJUSTMENT

Remove glove box door. Disengage cable from retaining clip, but DO NOT disconnect cable from crank arm. Move temperature selector lever to COOL position and hold in place. (Scheme 2) Push cable jacket to seat door, and install cable in clip. Test cable adjustment by moving lever to both ends of range and listening for door to seat.

BLOWER MOTOR INOPERATIVE

Check fuses. Check heater function selector switch. Check for battery voltage at blower motor. Check for open in blower motor ground circuit.

BLOWER MOTOR ONLY RUNS IN LOW

Check blower motor switch. Check wiring for open circuit. Check ground circuit for open circuit. Check for open blower motor resistor.

BLOWER MOTOR ONLY RUNS IN HIGH

Check for open blower motor resistor. Check for open thermal limiter. Check blower motor switch.

AIRFLOW FROM WRONG OUTLETS

Check for pinched, broken or improperly adjusted cable. Check for vacuum leaks and inoperative vacuum motor. Check for correct vacuum hose routing.

INSUFFICIENT HEAT

Ensure cooling system is operating properly. Check heater system hoses and core for coolant flow. Check for loose or misaligned cable to temperature blend door.

Note. If temperature selector lever cannot be moved, check for red cam retaining pin not removed during vehicle assembly.

ERRATIC FUNCTION MODE SELECTION

1. Check for vacuum source at engine manifold and vacuum canister. Ensure check valve is installed correctly. Check for leak at vacuum controller. Ensure all vacuum hoses are correctly routed and connections are tight.
2. Check vacuum motors and vacuum hoses for leaks and collapse. Check all mode doors for binding and foreign material. Check blower motor for foreign material and binding.

TESTING

BLOWER MOTOR VOLTAGE TEST

1. Place temperature selector lever in WARM position and function selector lever in FLOOR position. Connect voltmeter probes to connector at rear of blower motor.
2. With engine running, measure voltage drop across motor. Voltage reading for each blower switch position should be as specified. See «BLOWER MOTOR TEST SPECIFICATIONS»(/ford/econoline-e350/1985-1999/remont/heater/#heater-system) table.

BLOWER MOTOR CURRENT DRAW TEST

1. Separate blower motor ground (Black) wire at blower motor resistor. Connect positive ammeter lead to female spade connector and negative ammeter lead to resistor terminal.
2. Place temperature selector lever in midrange position and function selector lever in FLOOR position. Turn ignition on. Blower current draw (amperage) should be as specified. See «BLOWER MOTOR TEST SPECIFICATIONS»(/ford/econoline-e350/1985-1999/remont/heater/#heater-system) table.

BLOWER MOTOR TEST SPECIFICATIONS

FUNCTION SELECTOR VALVE

Place function selector level in specified position. (Scheme 1) Using a vacuum gauge, check for presence or absence of vacuum as specified. If test results are not as specified, check for kinked or broken vacuum lines. If vacuum lines are okay, replace function selector valve.

Scheme 1

REMOVAL & INSTALLATION

Scheme 2

Scheme 3

1. Remove trim applique and 3 screws retaining control panel assembly to mounting bracket. (Scheme 2) Carefully pull control panel assembly from opening. Disconnect electrical connectors, vacuum hoses and illumination bulb.
2. Remove push-on vacuum hose retaining clips from vacuum selector, and remove harness. (Scheme 3) Remove temperature control cable from control assembly. Using needle-nose pliers, compress retaining ears of bullet-type cable retainer. Cable "S" bends are removed from bottom side of levers by rotating cable 90 degrees to lever. To install, reverse removal procedure.

INSTRUMENT PANEL

1. Disconnect negative battery cable. Separate bulkhead electrical connector. Remove left and right inside windshield moldings. Remove engine cover. Remove steering column molding. Remove steering column opening cover, opening reinforcement and column shrouds.
2. Remove right lower trim panel. Remove left and right cowl trim panels. Remove parking brake assembly, but DO NOT disconnect cable. Disconnect right side wiring, radio antenna lead and brake warning light switch connector.
3. Disconnect heater control cable and vacuum lines. Remove right and center instrument panel attaching bolts. Remove steering coupler pinch bolt, and separate steering shafts. Disconnect shift cable.
4. Remove attaching screws from top of panel. Have an assistant support panel and move it rearward. Disconnect any remaining wires and components. Working with an assistant, remove panel through driver-side door. To install, reverse removal procedure.

PLENUM ASSEMBLY

1. Remove instrument panel. See «INSTRUMENT PANEL»(/ford/econoline-e350/1985-1999/remont/heater/#heater-system__instrument-panel) under REMOVAL & INSTALLATION. Disconnect vacuum hoses from panel/defrost vacuum motor and floor/defrost vacuum motor. Remove retainers attaching center register duct and heater air outlet air duct to plenum.
2. Separate plenum from heater housing, center register duct and heater air outlet duct. Remove plenum assembly. Remove vacuum motors from plenum. To install, reverse removal procedure.

BLOWER MOTOR ASSEMBLY

Disconnect blower motor lead wire at wiring harness. Remove ground wire mounting screw from firewall and 4 screws from blower motor mounting plate. Carefully remove blower motor assembly. To install, reverse removal procedure.

HEATER CORE

1. Remove heater hoses from heater core in engine compartment. Plug hoses. Remove 2 screws retaining sound deadening panel to underside of instrument panel. Remove sound deadening panel.
2. Remove 4 screws from heater core cover. Remove heater core cover. Remove screw and retaining bracket at bottom of heater core. Remove heater core and seal from case. To install, reverse removal procedure.

AUXILIARY (REAR) HEATER ASSEMBLY

Remove third, fourth and fifth bench seats (if equipped). Drain cooling system. Disconnect heater hoses located under left side of body. Disconnect rear heater assembly harness connectors. (Scheme 4) Remove mounting bolts, and lift assembly off locating dowel pin. Remove assembly while guiding heater hoses through from underbody. To install, reverse removal procedure.

Scheme 4

AUXILIARY (REAR) HEATER CORE

1. Remove third, fourth and fifth bench seats (if equipped). Remove auxiliary heater cover attaching screws, and remove cover assembly. Remove strap retaining heater core in auxiliary heater case.
2. Drain coolant from radiator. Disconnect heater hoses from auxiliary heater core. Plug openings. Disengage wire assembly from auxiliary heater core seal. Slide heater core and seal assembly out of case. To install, reverse removal procedure.

See also:
• BLOWER MOTOR TEST SPECIFICATIONS
• INSTRUMENT PANEL