Heater System Dodge Ram I

DESCRIPTION

Note. For the purposes of this article, "Pickups" will also refer to Chrysler Motors Imports Ram-50.

The heater assembly on all models is located in the passenger compartment. A heater control valve is used to regulate coolant flow and heat output. The heater assembly contains the heater core, heater control valve, air ducts, blower motor and intake ducts. On all models except Pickups, the heater systems are a blend-air type.

The Raider is also equipped with a rear warm water type heater. Heater systems for the Pickups are inside-outside air changeover and hot water type.

OPERATION

Heater and fresh air operations are controlled by 4 different control levers. The control panel consists of a mode control lever for inside/outside air, temperature control, air selector and a multi-speed blower switch. The temperature control opens and closes a heater control valve which determines heat output.

The heater mode control directs heated air to the windshield when in "DEF" position, to the floor when in "HEAT" position, or to the center ventilation ducts when in "VENT". Bi-level output is possible by positioning the lever between "VENT" and "HEAT".

The rear heater on Raider models blows warm both forward and backward. This provides a properly distributed air flow rate to provide comfortable heating. The rear heater switch, located under the center of the rear seat, has a single lever which serves the combined purposes of the heater fan switch and heater control lever.

The control panel consists of a mode control lever, temperature control and a multi-speed blower switch. The temperature control opens and closes a heater control valve which determines heat output.

TEMPERATURE CONTROL LEVER

Temperature level is selected by sliding lever left or right. The highest heat setting is when selector lever is at the "WARM" position. With temperature lever set at "COOL" position, ambient air is used for ventilating.

AIR SELECTOR

This lever is used to select the source of air flow into the car. With the lever set at "OUTSIDE" position, outside air is allowed to enter and/or pass through the heater. With lever set at "INSIDE" position, air is recirculated inside the passenger compartment.

BLOWER SWITCH

The blower can be operated at different fan speeds to regulate the amount of air forced through the vehicle. The fan speed will increase as the switch is turned or moved to the right.

HEATER CONTROL VALVE

Place control lever at "OFF" position. Connect the cable to the heater control valve with the valve fully closed. Secure the cable sleeve with clips. With the engine running, check for coolant leaks and check operation of heater control valve. If heater control valve does not operate properly, adjust by moving cable sleeve forward or backward at the retaining clip.

INSIDE/OUTSIDE CONTROL

Place control lever in the "INSIDE" position. Connect the cable to the damper lever with the outside air intake to the heater closed. Apply multi-purpose grease to rotating portions and the sliding portions of the lever. Confirm the damper's operation by moving the control lever. If not correct, adjust by moving the outer wire at the clipped point.

MODE SELECTOR LEVER

Place control lever in the position for defroster operation and remove cable clip. Make sure defroster door is fully open. Secure cable sleeve with clips. Move lever to other positions and check to make sure it operates correctly. Adjust cable if necessary by moving the sleeve forward or backward at the retaining clip.

BLOWER MOTOR INOPERATIVE

Blown blower fuse. Blower motor improperly grounded. Improper switch and blower motor wiring connections. Foreign object in fan.

ABNORMAL SOUND FROM BLOWER MOTOR

Foreign object inside blower. Incorrect balance of blower motor or fan. Damaged blower fan.

INSUFFICIENT HEAT

Incorrect thermostat in cooling system. Improperly adjusted temperature control cable. Clogged heater core fins. Faulty heater control valve.

UNWANTED HEAT

Improperly adjusted temperature control cable. Faulty heater control valve.

NO TEMPERATURE REGULATION

Clogged or stuck heater control valve. Incorrect installation of heater control valve control cable. Incorrect adjustment of heater control valve link.

NO VENTILATION

Incorrect adjustment of changeover dampers. Duct connection loose.

DUST INSIDE OF VEHICLE

Ventilator duct connection malfunction. Incorrect adjustment of inside/outside air changeover damper.

BLOWER MOTOR SWITCH

Blower motor switch can be tested using an ohmmeter. Insert test leads into appropriate connector terminals and check continuity. See BLOWER SWITCH CONTINUITY CHART.

Blower Switch Continuity Testing Use ohmmeter to test switch. Scheme 1

BLOWER SWITCH CONTINUITY

BLOWER MOTOR

1. With ignition on, check fuses. If fuses are not good, check wiring harness for short circuits. If fuses are okay, go to next step.
2. Check for voltage between heater relay and ground circuit. If there is no voltage, check for broken wire between fuse block and heater relay. If there is voltage, go to next step.
3. If there is voltage at heater relay, check relay and replace if necessary. Disconnect blower motor connector. Set heater switch to either "LO", "MED" or "HI".
4. Check voltage between harness side of connector and vehicle ground. Voltage should be 12 volts. If there is 12 volts, go to step 5). If there is no voltage, check for continuity between resistor terminals. If there is no continuity, replace resistor.
5. If there is continuity between motor terminals at blower connector, check for proper ground circuit. If ground circuit is okay, check for blower motor malfunction. Replace blower motor if necessary.

HEATER ASSEMBLY

Note. Heater removal is for vehicles equipped with heater system only. For removal on vehicles equipped with air conditioning, see appropriate MANUAL A/C-HEATER SYSTEM article in the MANUAL A/C-HEATER SYSTEMS section.

Removal (Colt, Colt Vista)

Disconnect battery ground cable. Move lever to "WARM" position. Drain engine coolant. Remove instrument panel. Remove the uct between the heater unit and blower assembly. Disconnect the heater hose at heater assembly. Remove heater assembly.

Installation

To install, reverse removal procedure. Make sure that hoses are clamped tightly and heater control valve is open while cooling system is refilled.

Removal (Conquest)

1. Remove steering wheel and column switch from steering shaft. Remove instrument cluster assembly. Remove front and rear console box assembly. Remove cover under instrument panel and glove box.
2. Insert tip of removal tool (MB990784) into space between instrument panel side cover and instrument panel side pad. Twist tool to remove left and right instrument panel side covers. Remove hood lock release handle and fuse block.
3. Insert a screwdriver from door glass side, and twist and pry side defroster grille forward to pull it out. Remove heater control knob. Remove screws, bolts and speed nuts from instrument panel.
4. Remove ash tray and light connector. Remove side defroster duct at instrument panel side. Remove main wiring harness connector for glove box, rear defogger, cigar lighter, rear wiper and rheostat.
5. Remove clock and pull instrument panel outward. Remove center reinforcement bolts. Loosen clamp for main harness. Remove panel.
6. Remove center ventilator duct, defroster duct, and lap heater duct. Remove center reinforcement bracket. Remove heater unit.

1. To install, reverse removal procedure. Install heater hoses and tighten clamps. The hose with painted mark should be connected to engine side.
2. Hook instrument panel on guide pin on dash board. Check to be sure that ventilator duct and wiring harness are correctly installed.
3. When glove box is being installed, first temporarily tighten each screw. After checking left and right clearances between glove box lid and instrument pad while lid is locked, tighten screws completely.
4. Place air outlet changeover lever at closed position. With heater side air outlet changeover damper lever in position, connect inner cable to lever and secure cable casing with clips.
5. Place heater control lever at the off position. Connect inner cable to lever and secure cable with clips.
6. Place inside/outside air changeover lever at fresh air position. With heater side inside/outside air changeover damper lever in position, connect inner cable to lever and secure cable with clips. Check all control cable adjustments and replenish coolant level.

Removal (Raider - Front)

1. Move temperature control lever to "WARM" position. Drain coolant from vehicle. Disconnect heater hoses from heater unit.
2. Remove steering wheel, center console, instrument cluster, lap heater ducts and release cable bracket. Remove fuse block, front speaker harness, right and left demister grilles.
3. Remove glove box and disconnect heater relay from front of wiring harness. Remove instrument panel mounting screws and remove instrument panel.
4. Remove center ventilator duct and defroster duct. Remove heater unit.

Removal (Raider - Rear)

Drain coolant. Disconnect rear heater electrical connectors. Disconnect heater hoses at rear heater. Remove grommet upward. Removecover mounting bolts. Remove cover. Remove rear heater assembly upward. Remove heater hose attaching clamps. Remove heater hoses attaching clips. Remove heater hose assembly.

Removal (Pickups)

1. Disconnect battery ground. Place heater control lever in "OFF" position. Drain coolant. Remove parcel tray, center ventilator grille and duct, and defroster duct.
2. Disconnect all control cables at heater side. Disconnect heater hose and harness from heater fan motor. Remove top mounting bolts and center mounting nuts and remove heater assembly.

Installation (Raider & Pickups)

1. Reverse removal procedure to install. Insert heater hoses fully into pipes and clamp them securely so they will not leak. When filling radiator with coolant, first open heater control valve fully and run engine to circulate coolant and discharge air from inside the heater and engine cooling system. Then stop engine and add coolant.
2. Adjust all control cables. When installing heater hose grommets, apply drying sealer. After installing heater control assembly, make sure each lever operates smoothly.

1. Remove upper and lower glove boxes. Disconnect the Inside/Outside air control wire from the left side of the blower assembly. Disconnect the side cover (driver's side) and lap heater duct.
2. Disconnect the heater control valve wire from the left side of the heater unit. Remove the meter assembly. Remove the left side defroster duct. Disconnect the air outlet changeover control wire from the left side of the heater unit.
3. Remove the heater control panel cover. Pull out the knob. Remove control panel mounting screws. Turn and remove the illumination lamp at the back of the heater control panel.
4. Remove the control panel. Remove the heater control assembly mounting screws. Draw out the heater control assembly slightly. Disconnect the fan switch connector. Remove the heater control assembly.

To install, reverse removal procedure. Adjust cables as necessary. Apply multi-purpose grease to rotating or moving parts of the control assembly.

Remove instrument panel and floor console. Remove left side defroster nozzle. Disconnect the heater fan switch harness connectors and optical fiber light harness connector (if equipped). Disconnect the heater control cables from the heater unit and blower assembly. Remove the optical fiber from the heater fan switch. Remove the control assembly.

To install, reverse removal procedure. Adjust cables as necessary. Apply multi-purpose grease to rotating or moving parts of the control assembly.

Removal (Montero)

1. Remove heater control knob and heater fan switch knob. Remove center console. Remove defroster nozzle at temperature control cable side.
2. Remove lap heater duct and glove box stopper and push glove box forward and down. Disconnect inside/outside control cable from blower assembly.
3. Disconnect control cables from heater unit. Remove heater control assembly mounting screws and pull out assembly slightly.
4. Disconnect heater fan switch harness connectors. Remove heater control assembly. Remove heater fan switch from heater control assembly.

1. Place air outlet changeover lever at closed position. With heater side air outlet changeover damper lever in position, connect inner cable to lever and secure cable casing clips.
2. Place heater control lever at off position. With heater side heater control valve control lever in position, connect inner cable to lever and secure cable casing with clips.
3. Place inside/outside air changeover lever at "INSIDE" position. With heater side inside/outside air changeover damper lever in position, connect inner cable to lever and secure cable casing with clips.
4. Set control lever to each position to check for correct operation. If not correct, adjust by moving outer wire at clipped point.
5. Check to make sure that each control lever moves smoothly. If there is any noise or stiff movement, apply multi-purpose grease to all moving parts.

Note. When mounting heater control assembly to instrument panel, tighten upper bolts to instrument panel so that they also secure center panel.

Remove cluster panel. Remove all control cables at the heater. Remove the heater control assembly.

To install, reverse removal procedure, adjusting cables as necessary.

1. Remove screws attaching right side console cover and remove side cover. Remove screw from lap heater duct. Disconnect duct and remove it.
2. Push sides of glove box inward until glove box will clear frame and swing down. Remove glove box. The glove box should be removed with lower frame attached.
3. Disconnect glove box switch harness at round topped terminal. Remove lap heater duct. Remove under tray stay. Disconnect duct joint. Loosen duct joint tightening bolt to free duct joint.
4. Remove left side defroster nozzle. Disconnect heater fan switch harness connectors and optical fiber light harness connector if equipped. Disconnect heater control cables from heater and blower assembly.
5. Remove optical fiber from heater fan switch. Remove heater fan switch. Disconnect A/C switch harness and air conditioner harness (if equipped). Disconnect drain hose and piping at piping connection projecting from firewall in engine compartment.
6. Remove heater assembly attaching nuts. Remove heater assembly top attaching bolts and remove heater assembly.

1. Connect each control cable and damper lever. For air outlet changeover system, place air outlet changeover lever at the "VENT" position. With the heater side air outlet changeover damper lever in the down position, connect inner cable to lever and secure cable casing with securing clips.
2. For heater control valve, place the control lever at the off position. With heater side heater control valve control lever in the down position, connect inner cable to the lever and secure cable.
3. For the inside/outside air changeover system, place the inside/outside air changeover lever at the "OUTSIDE" position. With the heater side inside/outside air changeover damper lever in the down position, connect inner cable to the lever and secure cable casing.
4. Check to make sure that each control lever moves smoothly. If there is any noise or stiff movement, apply multi-purpose grease to all moving parts.

Removal (Colt Vista)

Remove the cover. Disconnect links. Remove pipe clamps. Remove heater core from heater unit.

To install, reverse removal procedure. Confirm and make adjustment of each cable as necessary. Heater hoses should be inserted with a 1-1.2" (25-30 mm) overlap on outlet.

Removal & Installation (Colt)

Remove heater hose. Remove pipe clamps. Remove water valve. Remove heater core from heater unit. Reverse procedure for installation.

Removal (Raider)

Remove the heater control lever arm. Remove the heater control valve cover. Remove the heater pipe and heater control valve. Disconnect the control arm linkage. Remove the control arm. Remove the heater core by moving it sideways.

To install, reverse removal procedure. Connect heater hoses with 1-1.2" (25-30 mm) overlap on outlet.