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Heater System: Other Mazda MX-5 NA

Heater 2 illustrations ~760 words

AIRFLOW MODE DOOR

Set airflow mode control lever at vent position. Disconnect control cable at airflow mode door lever. see scheme 1 Extend airflow mode door lever until it stops. Attach control cable to door lever. Secure cable using clip. Ensure control lever slides freely between defrost and vent positions.

AIR-MIX (TEMPERATURE BLEND) DOOR

Set temperature control lever at maximum hot setting. Disconnect control cable at air-mix door lever. see scheme 1 Extend air-mix door lever until it stops. Attach control cable to door lever. Secure cable using clip. Ensure control lever slides freely between hot and cold settings.

FRESH/RECIRCULATED AIR DOOR

Set fresh/recirculated air control lever at fresh air setting. Disconnect control cable at fresh/recirculated air door lever. Retract recirculated/fresh air door lever until it stops. Attach control cable to door lever. Secure cable using clip. Ensure control lever slides freely between recirculated air and fresh air settings.

BLOWER MOTOR CIRCUIT

  1. Check 30-amp HEATER circuit breaker in passenger compartment fuse block. If Red button has not popped out, go to next step. If Red button has popped out, repair short circuit in wiring harness, then press Red button to reset circuit breaker.
  2. Turn ignition on. Turn blower switch to 4th position (high). Using voltmeter, backprobe Blue wire terminal of blower motor connector on bottom of blower case. If battery voltage exists, go to next step. If no voltage is present, repair wiring harness from circuit breaker, through blower motor relay, to blower motor. If necessary, test blower motor relay. See «BLOWER MOTOR RELAY»(ref-36726-S39020839052001010900000) . NOTE: Blower resistor uses 1-pin and 4-pin connectors. Wire in 1-pin connector is Blue/Red, and one of the wires in 4-pin connector is also Blue/Red. Check voltage at appropriate wire.
  3. Turn blower switch off. Ensure ignition is on. Backprobe Blue/Red wire terminal of blower resistor 1-pin connector. If battery voltage exists, go to next step. If voltage is not present, replace blower motor.
  4. Backprobe Blue/White wire terminal of blower resistor 4-pin connector. If battery voltage exists, go to next step. If voltage is not present, replace blower resistor.
  5. Backprobe Blue/Red wire terminal of blower resistor 4-pin connector. If battery voltage exists, go to next step. If voltage is not present, replace blower resistor.
  6. Backprobe Blue/Green wire terminal of blower resistor 4-pin connector. If battery voltage exists, go to next step. If voltage is not present, replace blower resistor.
  7. Backprobe Blue/Yellow wire terminal of blower resistor 4-pin connector. If battery voltage exists, go to next step. If voltage is not present, replace blower resistor.
  8. Turn blower switch to 4th position (high). Backprobe Black wire terminal of blower switch connector. If voltage is not present, go to next step. If battery voltage exists, repair Black wire between blower switch and body ground.
  9. Turn ignition blower switch off. Backprobe Blue/White wire terminal of blower switch connector. If battery voltage exists, go to next step. If voltage is not present, repair Blue/White wire between blower resistor and blower switch.
  10. Backprobe Blue/Red wire terminal of blower switch connector. If battery voltage exists, go to next step. If voltage is not present, repair Blue/Red wire between blower resistor and blower switch.
  11. Backprobe Blue/Green wire terminal of blower switch connector. If battery voltage exists, go to next step. If voltage is not present, repair Blue/Green wire between blower resistor and blower switch.
  12. Backprobe Blue/Yellow wire terminal of blower switch connector. If battery voltage exists, replace blower switch. If voltage is not present, repair Blue/Yellow wire between blower resistor and blower switch.

BLOWER MOTOR

Disconnect blower motor 2-pin connector from bottom of blower case. Apply battery voltage across blower motor terminals. Replace blower motor if it does not operate.

BLOWER MOTOR RELAY

  1. Disconnect blower motor relay connector. Using ohmmeter, check continuity between relay terminals "A" (Blue/White wire) and "B" (Blue wire). (Scheme 2) Continuity should not exist.
  2. Check continuity between relay terminals "C" (Blue wire) and "D" (Black/Red wire). Ensure continuity exists. Apply battery voltage between terminals "C" and "D". Ensure continuity exists between terminals "A" and "B" with battery voltage applied. Replace relay if continuity is not as specified.

Scheme 2

Scheme 2
Scheme 2

BLOWER RESISTOR

Disconnect blower resistor connectors from blower case. Check continuity, in turn, between Blue/Red wire terminal of 1-pin connector and each terminal of 4-pin connector. Ensure continuity exists. Replace resistor if continuity does not exist.

BLOWER SWITCH

Disconnect blower switch connector. Place blower switch in indicated positions, and check continuity between specified blower switch terminals. See BLOWER SWITCH TEST table. see scheme 4 If continuity is not as specified, replace blower switch.

Switch PositionContinuity Between Terminal No.
Off(1)
Low"A" & "G"
Medium-Low"C", "G" & "H"
Medium-High"E", "G" & "H"
High"B", "G" & "H"
(1) There should not be continuity between any terminals.
(1)There should not be continuity between any terminals.

BLOWER SWITCH TEST

Scheme 3

Scheme 3
Scheme 3

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