Mitsubishi Montero (1991+). Manual - part 19

A/C-HEATER SYSTEM - MANUAL 



1991 Mitsubishi Montero

         1991 MANUAL A/C-HEATER SYSTEMS

         Chrysler Motors, Mitsubishi

         Chrysler Motors: Colt Vista, Ram-50

         Mitsubishi: Montero, Pickup

         * PLEASE READ THIS FIRST *

CAUTION: When discharging air conditioning system, use only approved

         refrigerant recovery/recycling equipment. Make every attempt

         to avoid discharging refrigerant into the atmosphere.

         A/C SYSTEM SPECIFICATIONS

SPECIFICATIONS TABLE

Compressor Type

  Colt Vista & Montero  ....................  Nippondenso 10-Cyl.

  Pickup & Ram-50  ...............................  Sanden Scroll

Compressor Belt Deflection

  Colt Vista  ............................  11/32-7/16" (8-11 mm)

  Montero  .............................  21/64-3/8" (8.5-9.5 mm)

  Pickup & Ram-50  ....................  21/64-25/64" (8.5-10 mm)

Compressor Oil Capacity

  Colt Vista & Montero  ...............................  2.7 ozs.

  Pickup & Ram-50  ....................................  5.0 ozs.

Refrigerant (R-12) Capacity

  Colt Vista & Montero  ................................  32 ozs.

  Pickup & Ram-50  .....................................  30 ozs.

System Operating Pressures (1)

  Colt Vista, Pickup & Ram-50

   High Side  ....................  130-220 psi (9.1-15.5 kg/cm



)

   Low Side  ........................  20-26 psi (1.4-1.8 kg/cm



)

  Montero

   Dual Unit

     High Side  ..................  142-199 psi (9.9-14.0 kg/cm



)

     Low Side  ......................  16-30 psi (1.1-2.1 kg/cm



)

   Single Unit

     High Side  ...................  102-142 psi (7.1-9.9 kg/cm



)

     Low Side  ......................  18-32 psi (1.3-2.2 kg/cm



)

(1) - With ambient temperature at least 80



F (27



C).

         DESCRIPTION

         Slight variations exist among the manual A/C-heater systems

used. Either Sanden Scroll or Nippondenso 10-cylinder compressor is

used. Cycling of the compressor clutch is controlled by switches which

monitor temperatures and pressures.

         Compressors will only operate within the normal operating

temperatures and pressures set for each model. An electric condenser

fan operates whenever A/C system is operating. System components used

vary depending upon model. Most systems include an A/C compressor

control unit, fan switch, evaporator, temperature sensor, high and low

(or dual) pressure switch, engine coolant temperature switch,

compressor, condenser, receiver-drier and various pipes and hoses.

         OPERATION

         A/C SWITCH

         The A/C switch is located in the lower, center section of

control panel. See Fig. 1. When switch is pushed, air conditioning

will operate if blower motor control lever is in a position other than

OFF.

         When activated, the A/C button/switch allows the A/C

compressor clutch to engage and operate the compressor. On some

models, a light on the button will glow when button/switch is

activated.

Fig. 1:  A/C Switch & Control Panel

Courtesy of Mitsubishi Motor Sales of America.

         AIR SELECTOR LEVER

         The air selector lever is located in the upper, left corner

of control panel and moves horizontally to select the source of air

needed inside of passenger compartment. Lever moves from OFF position

on the left to the outside air mode, to the mixture of both outside

and inside air mode, and to the recirculation mode on the right. Lever

should normally be set in the recirculation mode for maximum A/C

cooling.

         BLOWER MOTOR CONTROL LEVER

         Blower motor control lever is located on the lower, left

corner of control panel and moves horizontally to select blower motor

speeds. As lever is moved from far left or OFF position, increasing

speeds of blower operation are selected. In order for A/C system to

operate, blower motor control lever MUST be in a position other than

OFF.

         MODE SELECTOR LEVER

         Mode selector lever is located in upper right corner of

control panel. Either 2 or 6 modes are available to achieve desired

distribution of air from various outlets.

         On all models, air is directed to windshield and side

windows and comes out from the panel outlets when mode selector lever

is positioned to the far left. When lever is moved one detent to the

right, air is directed to windshield and side windows simultaneously.

         On 6-mode models, air is directed to floor area, windshield,

and side windows when lever is moved 2 detents to the right. When

lever is moved 3 detents to the right, air is directed to floor area.

When lever is moved to the second to last detent on control panel, air

is directed to floor area and panel outlets. When lever is in the far

right position, air will be directed to panel outlets only.

         TEMPERATURE CONTROL LEVER

         The temperature control lever operates blend-air door in the

heater/air conditioning unit, mixing cooled and heated air so the

selected air temperature can be obtained. The system will provide

cooled air when A/C switch is in ON position and blower motor is in

any position other than OFF. The temperature control lever should be

in the far left (maximum cooling) side of temperature selection scale

when maximum A/C cooling is desired.

         DUAL PRESSURE SWITCH

         The dual pressure switch, located in the refrigerant line

near condenser, is wired in series with compressor clutch. Whenever

system pressures drop below or increase above the control point of the

switch, power supplied to compressor will be cut and compressor

activity will cease until pressures are back to within operating

ranges.

         ENGINE COOLANT TEMPERATURE SWITCH

         The engine coolant temperature switch, located on thermostat

housing, is wired in series with compressor clutch. When coolant

temperature is greater than switch control temperature, power to

compressor is cut and compressor is turned off until temperature

returns to operating range.

         EVAPORATOR THERMISTOR

         The evaporator thermistor, attached to evaporator fins, is

wired in series with compressor clutch and prevents evaporator

freezing. Power to compressor clutch is cut if control temperature is

exceeded, allowing evaporator to thaw. When temperature returns to

operating range, thermistor allows power to compressor clutch.

         FUSIBLE PLUG

         A fusible plug, located on receiver-drier, melts and allows

refrigerant to escape when ambient temperatures in engine compartment

reach 221



F (105



C). Once fusible plug has blown, it cannot be reused

and must be replaced.

         HIGH PRESSURE SWITCH

         The high pressure switch, installed in refrigerant line, is

wired in series with compressor clutch. When refrigerant pressures

rise above switch control pressure point, power to compressor clutch

is cut. The high pressure switch may also be activated when airflow

through condenser is blocked or when system is overcharged.

         HIGH/LOW PRESSURE CUT-OFF SWITCH

         The High/Low Pressure Cut-Off (HLPCO) switch, located on

refrigerant line, is wired in series with compressor clutch. Switch

cuts off power to compressor clutch when refrigerant pressures are

above or below switch control point. When pressure returns to normal

operating range, compressor clutch operation resumes.

         LOW PRESSURE SWITCH

         The low pressure switch, located in receiver-drier, is wired

in series with compressor clutch. When refrigerant pressure drops

below switch control point (usually due to leak in system), power to

compressor clutch is cut.

         REFRIGERANT TEMPERATURE SWITCH

         The refrigerant temperature switch, located on rear of

compressor, detects refrigerant temperature discharged from

compressor. A/C Control Unit (ACCU) uses this information to control

compressor clutch cycling.

         ADJUSTMENTS

NOTE:    For adjustment procedures not covered in this article, see

         appropriate HEATER SYSTEM article in the AIR CONDITIONING &

         HEAT Section.

         MODE CONTROL CABLE

         Montero

         Move mode selector lever to far left (DEF) position. Move

mode door lever upward in direction indicated by arrow. See  Fig. 2.

Connect inner wire to lever, and secure outer housing using clip.

Operate mode control knob to ensure proper operation.

Fig. 2:  Adjusting Mode Selection Cable (Montero)

Courtesy of Mitsubishi Motor Sales of America.

         TEMPERATURE CONTROL CABLE