Heater System Chevrolet Chevy Van G10

MODEL IDENTIFICATION

Adjustment and repair procedures in this article are referred to by model name or series. The following table lists General Motors model name and series designation.

MODEL DESIGNATION

GENERAL MOTORS MODEL DESIGNATION

DESCRIPTION

System is a blend-air type. Outside air is heated and then mixed with cooler outside air to attain desired temperature. System consists of a blower and an air inlet assembly, heater air distributor assembly and heater control panel.

Blower, air inlet assembly and heater hoses are located on the engine side of firewall while heater core and distributor duct are on passenger side. System has no heater control valve. Coolant circulation keeps heater core hot at all times.

Operation of blower motor is controlled by the fan switch. The motor is connected in series with the fan switch and blower resistor assembly.

On Van and Suburban models, an auxiliary heater is available for heating rear of vehicle. The unit operates independently of standard heater and has its own set of controls. Heater hoses connect at the standard heater and extend to the auxiliary heater. A vacuum-operated heater control valve is installed in inlet line in engine compartment to cut off coolant flow when heat is not desired. (Scheme 8)and (Scheme 9).

TEMPERATURE CONTROL LEVER

The lower lever on the control panel controls discharge air temperature in all mode positions. Full right position provides maximum heat. Full left position provides cool (outside) air.

MODE CONTROL LEVER

When lever is in "VENT" position (if equipped), all discharge air is directed to the upper outlets. The "DEF" position directs most of the air to windshield (defroster) outlets with some directed into the flow (heater) outlets. When in "HEATER" position, most of the air is delivered through the floor outlets with some air flow to windshield outlets.

BLOWER CONTROL

Blower control can be either knob or lever type. Knob is a 4-speed type rotating from "OFF" to "HI". Lever is a variable speed type, sliding from "OFF" through "LO" to "HI".

AUXILIARY HEATER BLOWER SWITCH

A 3-speed blower switch is located in instrument panel, to right of steering column. When switch is in "OFF" position, auxiliary system will not operate.

CONTROL CABLES

Note. Information Not Available for "C" & "K" Series.

"R" & "V" Series

Disconnect battery ground cable. Remove glove box and glove box door assembly. Pry off cable clip eyelet with pliers and disconnect cable from door. Remove cable retaining screw. While holding cable with pliers, rotate mounting tab on cable to lengthen or shorten cable.

"L", "M" & "G" Series

Attach cable core wire and cable housing to control panel. Move temperature control lover to cool position and attach loop on cable core wire to temperature door on heater case. Attach cable housing to heater/defroster assembly. Move temperature control lever to full heat position to adjust cable.

"S" & "T" Series

Remove control panel. Disconnect control cables at both ends. Replace cables and install control panel. Cycle control lever through its full range of travel to adjust cable.

Removal & Installation ("G" Series)

1. Disconnect battery ground cable. Remove instrument panel bezel. Remove control panel-to-instrument panel retaining screws. Carefully pull control panel rearward far enough to gain access to cables.
2. Disconnect control cables, light bulb and blower switch connector. Remove control panel from vehicle. Remove blower switch attaching screws and remove blower switch. To install, reverse removal procedure.

Removal & Installation ("S" & "T" Series)

Disconnect battery ground cable. Remove instrument panel center bezel. Remove control panel screws and pull control out. Disconnect electrical connection and cables from control panel. Remove blower switch from control panel. To install, reverse removal procedure.

Removal & Installation ("C", "K", "L", "M", "R" & "V" Series)

Disconnect battery ground cable. Remove instrument panel bezel. Disconnect control cables and blower switch electrical connectors. Remove control panel through opening above it. Remove blower switch attaching screws and blower switch. To install, reverse removal procedure.

Removal & Installation ("L" & "M" Series)

Disconnect battery ground cable. Drain coolant. Remove coolant bottle. Remove bolts from washer bottle and move out of way. Remove heater hoses at core and plug openings. Remove core cover attaching screws. Remove heater core retaining straps and remove core. To install, reverse removal procedure. (Scheme 1)

Scheme 1

Removal & Installation ("R" & "V" Series)

1. Disconnect battery ground cable. Drain cooling system. Disconnect heater hoses at heater core, drain core into pan and plug openings. Remove nuts from heater distributor duct studs. Remove glove box and glove box door assembly. Disconnect control cables.
2. Remove floor outlet. Remove defroster duct-to-heater distributor duct screw. Remove heater distributor-to-firewall screws. Pull assembly rearward to gain access to wiring harness. Disconnect all harness connectors attached to assembly. (Scheme 2)
3. Remove assembly from vehicle. Remove heater core retaining straps and remove cores. To install, reverse removal procedure. Ensure seals are intact before installing.

Exploded View Of HVAC Module. Scheme 2

Removal & Installation ("C" & "K" Series)

1. Disconnect battery ground cable. Drain cooling system. Remove coolant recovery tank. Disconnect heater hoses at core. Disconnect cable from antenna mast. Remove glove box.
2. Disconnect wiring harness from ECM. Remove ECM and bracket. Remove right kick pad. Remove right lower dash panel bolt and nut. Remove heater case mounting bolts. Remove heater case from vehicle while raising instrument panel. Remove heater core from heater case. To install, reverse removal procedure. (Scheme 3)

Scheme 3

1. Disconnect battery ground cable. Drain cooling system. Remove coolant recovery tank. Disconnect heater hoses at core. Drain coolant into pan and plug openings. Remove screws attaching heater duct at case and engine cover. Remove duct.
2. Remove engine housing cover. Remove instrument panel attaching screws at windshield. Remove all lower screws and right lower instrument panel support bracket at door pillar. Remove engine cover. Lower steering column, then raise and support right side of instrument panel.
3. Remove defroster duct-to-heater distributor case attaching screw and screws attaching heater distributor to heater case. Disconnect temperature door cable and bolt back cable to provide access. Remove nuts at engine compartment side of heater distributor case and nut on passenger compartment side.
4. Remove heater case and core as an assembly. Tilt case assembly rearward at top while lifting up until core tubes clear dash openings. Remove core retaining straps and remove core. To install, reverse removal procedure. Ensure seals are intact before installing.

Disconnect battery ground cable. Drain engine coolant. Remove heater core hoses at core and plug core openings. Remove core cover attaching screws. Remove retainers at end of core. Remove core from vehicle. To install, reverse removal procedure. (Scheme 4)

Scheme 4

Disconnect negative battery cable. Disconnect blower electrical connections and remove coolant recovery bottle. Remove bolts from washer bottle and move out of way. Remove blower motor retaining screws and remove blower. To install, reverse removal procedure.

Disconnect negative battery cable. Disconnect electrical connectors at blower motor. Remove blower motor retaining screws and remove blower motor. To install, reverse removal procedure.

Removal & Installation ("C", "G", "K", "R" & "V" Series)

Disconnect battery ground cable. On Vans, remove coolant recovery tank and power antenna. On all models, disconnect blower motor lead wire. Remove blower motor mounting screws. Remove motor and wheel. If necessary, pry gently on the blower flange to remove. Remove blower wheel-to-motor shaft nut and remove wheel. To install, reverse removal procedure.

Removal & Installation ("L", "M", "S" & "T" Series)

Disconnect negative battery cable. Pull control panel out from dash. Disconnect cables at control panel and heater module. Remove cables. To install, reverse removal procedure. (Scheme 5)and (Scheme 6).

Removal & Installation ("C", "K", "R" & "V" Series)

Disconnect battery ground cable. Remove instrument panel bezel. Remove screws attaching control panel to instrument panel. Raise lower control panel and remove cable push nuts and tab attaching screws. Remove glove box and glove box door as an assembly. Remove cable from retaining clip and remove cable assembly. To install, reverse removal procedure. Check operation, and adjust if necessary. (Scheme 7)

1. Disconnect battery ground cable. Remove glove box assembly. Using pliers, pry off cable clip eyelet clip from control assembly and heater/defrost assembly. Unsnap flags from receivers on heater/defroster assembly and control panel assembly.
2. Remove cable retaining screws on back of heater/defroster assembly. To install, reverse removal procedure. Test operation and adjust if necessary.

Scheme 5

Scheme 6

Scheme 7

Scheme 8

Scheme 9