Tech Tip: Mazda MPV Temperature Difference Between Dash Vents – UnderhoodService

Tech Tip: Mazda MPV Temperature Difference Between Dash Vents

On some vehicles, the output air temperature may differ between the two center dash air vents (vents on either side of audio system). This condition usually occurs when the HVAC settings are in the following positions: A/C switch ON, in BI-LEVEL or VENT mode, Temperature Control Dial in 1 o'clock to 3 o'clock position (set for warm air).

Applicable Models: 2000-’05 MPV

On some vehicles, the output air temperature may differ between the two center dash air vents (vents on either side of audio system). This condition usually occurs when the HVAC settings are in the following positions: A/C switch ON, in BI-LEVEL or VENT mode, Temperature Control Dial in 1 o’clock to 3 o’clock position (set for warm air).

Customers with this concern should have their vehicle repaired using the following repair procedure.

Repair Procedure:figure 1
Using the service “plate” and modifying the HVAC cool-ing/heating unit will decrease the output air temperature difference between the center dash vents.

1. Verify customer concern.

2. Record the customer’s pre-set radio stations.

3. Remove the dashboard/cooling unit according to the MPV Workshop Manual (Section 07-11) Front A/C Unit Removal/Installation.figure 2

Front A/C Cooling Unit Modification:
1. Set the cooling unit on a work bench with the heater pipes pointing upward and the white heater duct facing toward you as shown in Fig. 1.

2. Remove the screw holding the heater duct to the cooling unit, then remove the duct.

figure 3 3. Carefully remove the black rubber gasket by peeling it off from the cooling unit.
Note: The gasket will need to be reused. Do not allow any dirt or debris to contact the gasket adhesive.

4. Remove the two screws holding the white plastic cover near the expansion valve, then remove the cover.

5. Remove the screw holding the small white plastic cover found on the opposite side, then remove the cover according to Fig. 2.

6. Remove the three screws holding the heater case, then remove the heater case according to Fig. 3.figure 4

7. Position the A/C cooling unit to remove the five screws and seven small clips holding the front evaporator cover according to Fig. 4.

8. Pull off the evaporator cover.

9. Remove the evaporator from the cooling unit and carefully set it aside to prevent any damage to the evaporator cooling fins.figure 5

10. Prepare to install the “plate” and modify the “case rib” area shown in Fig. 5.

11. Place shop rags under the blend door area.

12. Close the blend door and position plate so there is a 2 mm gap between the blend door and plate when the blend door is closed as shown in Fig. 6.figure 6

13. Using the plate as a template, hold it in position and mark the two holes for drilling. Warning: Be sure to wear safety glasses before drilling.

14. Drill two holes using a 5/32” drill bit.Figure 7

15. Attach the plate to the cooling unit case with two 5/32” pop rivets with 13 mm “grip range.”

16. Move the blend door back and forth to ensure the door is not binding on the plate.

17. Using a dremel tool, die grinder or hot knife, remove only the “shaded” portion of the case rib as shown in Fig. 7.

18. Remove the case rib portion and shop rags.

19. Remove all plastic debris from under the blend door and inside the cooling unit with compressed air.

20. Re-assemble the cooling unit in reverse order.

21. Re-install the cooling unit and dashboard ­assembly in the reverse order of removal.

22. Re-charge the A/C system and confirm that all dashboard and HVAC controls operate properly.

23. Re-enter customer’s pre-set radio stations.

24. Verify the repair.

Courtesy of ALLDATA.

You May Also Like

Auxiliary Water Pump Diagnostics

A car or truck comes into your shop with a complaint of poor heater performance. The driver complains that on cold mornings the heater will blow cold during the drive to work in rush hour traffic. The car is not overheating and the air is coming from the correct ducts. Your first reaction might be to install a new thermostat and inspect the heater core for a blockage. On the test drive, the system may perform great for you. Is the customer just cold blooded?

A car or truck comes into your shop with a complaint of poor heater performance. The driver complains that on cold mornings the heater will blow cold during the drive to work in rush hour traffic. The car is not overheating and the air is coming from the correct ducts.

VIDEO: Diagnosing The A/C Compressor Clutch

Andrew Markel discusses the clutch on the A/C compressor, and the signs to look for in your diagnostic to confirm its operation. Sponsored by Valeo.

Toyota FJ Cruiser Water Pump Replacement

Toyota’s original Land Cruiser was the company’s version of a Jeep that could go anywhere. In its time it was highly rated and collected, which led the Japanese juggernaut to bring back an updated SUV in 2007 called the FJ Cruiser. The retro-styled vehicle was again a go anywhere machine powered by a 4.0L V6 (1GR-FE) used in the Tacoma. The engines are durable and considered relatively robust for the time.

Long-Life Coolants Explained

Different types of coolants cover a range of applications from diesel to domestic, Asian and European vehicles. Each one is formulated to a specific manufacturer’s specifications to keep their engines at an optimal temperature. But, changes to the old one-size-fits-all formula has led to confusion for consumers and even some technicians.

VIDEO: Engine Efficiency Brings More Hoses

Andrew Markel discusses hoses and the necessity for several of them to route fluids to all parts of the vehicle due to the growing efficiency of engines. Sponsored by Dayco.

oil-coolant-hoses-video-featured

Other Posts

Climate Control Modules

HVAC control modules may fail when the contacts and switches become inoperable. Sponsored by The Group Training Academy.

LIQUI MOLY Releases A/C System Cleaner

The cleaning solution is designed to improve the efficiency and lifespan of HVAC systems.

Why Does Engine Coolant Need Replacement?

Two specifications can be used to justify replacement — the condition of the additive package & the freezing point.

Rotary Announces New A/C Recharging Equipment Line

Through its partnership with TEXA, Rotary will launch three new models in the spring of 2023.