How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Bob Your Own Question

Bob
Bob, Auto Tech
Category: Chevy
Satisfied Customers: 4087
Experience:  Plus 40 years GM, over 30 certified with Chevrolet, ASE certified Master Tech. (Expired, Retired)
2210118
Type Your Chevy Question Here...
Bob is online now
A new question is answered every 9 seconds

remove the heating/ventilation module from a 1999 s-10 blazer?

Customer Question

how do you remove the heating/ventilation module from a 1999 s-10 blazer?
Submitted: 7 years ago.
Category: Chevy
Expert:  Bob replied 7 years ago.
Tis one if tuff. It requires removing the complete dash pad and the right front inner fender panel. If you still feel you want to do the job, let me know if it has manual or automatic AC and repost here and I will send instructions.
Customer: replied 7 years ago.
I' ve got the dash out already but i had no idea the inner fender had to come out! automatic AC?
Expert:  Bob replied 7 years ago.

After you get the inner fender panel out of the way, you may be able to just take the rear half of it loose, there are 3 nuts, 10mm on the lower right side of the firewall one is so close to the exhaust manifold that you will need to use an end wrench on it. There is also a small heat shield between 2 of the nuts that is important to reinstall. These are on the bottom toward the passenger side of the firewall close to the right side exhaust manifold at the firewall. If you get in trouble or need other information, just yell. Post here and I will see it. One hidden nut behind the blower motor resistor, in the hole under it. Good luck.

Document ID# XXXXX
1999 Chevrolet S10 Pickup - 4WD

 

Heater/Vent Module Replacement

Removal Procedure


    Object Number: 281206  Size: SH

  1. Remove the instrument panel.
  2. Drain the engine coolant.
  3. On vehicles with automatic climate control only, cut (1) the outer layer of the A/C evaporator and blower module in order to access the service access cover. Refer to Blower Motor and Fan Replacement .
  4. On vehicles with automatic climate control only, remove the service access cover mounting screws.
  5. On vehicles with automatic climate control only, remove the service access cover.
  6. On vehicles without automatic climate control, remove the blower motor resistor.

    Important: Mark and use the same mounting bolt (located behind the A/C evaporator and blower module) for the heater assembly during the installation process. Other mounting bolts are longer and will obstruct the operation of the temperature door.

  7. Remove the heat/vent module mounting bolt through the blower motor resistor or service access cover opening.
    Object Number: 1595  Size: SH

  8. On vehicles with A/C only, remove the right wheel house panel.
  9. On vehicles with A/C only, raise and support vehicle.
  10. On vehicles with A/C only, remove the front right tire.
  11. On the Utility only, remove the A/C evaporator and blower module heat shield screws.
  12. On the Utility only, slide the A/C evaporator and blower module heat shield toward the front of the vehicle.
  13. Remove the 2 lower heat/vent module mounting nuts.
  14. On the Utility only, remove the A/C evaporator and blower module heat shield bracket.
  15. Remove the bottom right heat/vent module mounting bolt from inside the vehicle.

    Important: The heat/vent mounting stud has a flange on the inside and cannot be removed from under the hood. Stop turning the stud after the threads are off the heat/vent module.

  16. On the Utility only, while an assistant inside the vehicle pulls the bottom right corner of the heat/vent module approximately 1 inch back, remove the 2 heat/vent module mounting studs.
  17. On vehicles with A/C only, lower the vehicle.
    Object Number: 529580  Size: SH

  18. On vehicles with a 2.2L engine only, remove the engine wiring harness bracket located at the rear of the intake manifold.
  19. Remove the heat/vent module mounting bolt located at the lower left side of the heater core to heater hose connection.
  20. Remove the heat/vent module mounting nut located at the lower right side of the heater core to heater connection.

    Important: The heat/vent mounting stud has a flange on the inside and cannot be removed from under the hood. Stop turning the stud after the threads are off the heat/vent module.

  21. On the Utility only, loosen the heat/vent module mounting studs until the threads are free from the heat/vent module.
  22. Disconnect all of the electrical connectors from the heat/vent module.
  23. Disconnect all of the vacuum lines from the heater assembly.
  24. Disconnect the heater hoses from the heater core.
  25. Remove the heat/vent module from the vehicle.

Installation Procedure


    Object Number: 529580  Size: SH

  1. If replacing the heat/vent module, transfer the components from the old heat/vent module as necessary.

    Important: Before installing the heat/vent module to the vehicle, ensure that the heat/vent module mounting studs are located in the proper positions.

  2. Install the heat/vent module to the vehicle.
  3. Connect the heater hoses to the heater core.
  4. Connect all of the vacuum lines to the heater assembly.
  5. Connect all of the electrical connectors to the heat/vent module.
  6. Install the bottom right heat/vent module mounting bolt from inside the vehicle approximately halfway into the threads.

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  7. On the Utility only, install the heat/vent module mounting stud located at the lower right side of the heater core to heater hoses connection in the engine compartment.

    Tighten
    Tighten the heat/vent module mounting stud to 4.5 N·m (22 lb in).

  8. On vehicles with A/C only, raise the vehicle. On the Utility only, install the bottom right heat/vent mounting studs. Ask an assistant to pull the bottom right corner of the heat/vent module back from inside the vehicle.
  9. Tighten
    Tighten the heat/vent module mounting studs to 4.5 N·m (22 lb in).

  10. On the Utility only, install the A/C evaporator and blower module heat shield bracket.
  11. Install the heater/vent module mounting nuts.

    Tighten
    Tighten the heat/vent module mounting nuts to 4.5 N·m (22 lb in).

  12. On the Utility only, slide the A/C evaporator and blower module heat shield into the original position.
  13. On the Utility only, install the A/C evaporator and blower module heat shield screws.

    Tighten
    Tighten the A/C evaporator and blower module heat shield screws 2.2 N·m (19 lb in).


    Object Number: 1595  Size: SH

  14. On vehicles with A/C only, install the right front tire.
  15. On vehicles with A/C only, lower the vehicle.
  16. Install the bottom right heat/vent module mounting bolt from inside the vehicle.

    Tighten
    Tighten the heat/vent module mounting bolt to 4.5 N·m (22 lb in).

  17. On vehicles with A/C only, install the right wheel house panel.
    Object Number: 529580  Size: SH

  18. Install the heat/vent module mounting nut located at the lower right side of the heater core to heater connection.

    Tighten
    Tighten the heat/vent module mounting nut to 4.5 N·m (22 lb in).

  19. Install the heat/vent module mounting bolt located at the lower left side of the heater core to heater hose connection.

    Tighten
    Tighten the heat/vent module mounting bolt to 4.5 N·m (22 lb in).

  20. On vehicles with the 2.2L engine only, install the engine wiring harness bracket located at the rear of the intake manifold.
    Object Number: 281206  Size: SH

    Important: Mark and use the same mounting bolt (located behind the A/C evaporator and blower module) for the heater assembly during the installation process. Other mounting bolts are longer and will obstruct the operation of the temperature door.

  21. Install the heat/vent module mounting bolt through the blower motor resistor or service access cover opening.

    Tighten
    Tighten the heat/vent module mounting bolt to 4.5 N·m (22 lb in).

  22. On vehicles without automatic climate control, install the blower motor resistor.
  23. On vehicles with automatic climate control only, install the service access cover.
  24. On vehicles with automatic climate control only, install the service access cover mounting screws.
  25. On vehicles with automatic climate control only, install the outer layer of the A/C evaporator and blower module. Refer to Blower Motor and Fan Replacement .
  26. Refill the engine coolant.
  27. Install the instrument panel.

Document ID# XXXXX
1999 Chevrolet S10 Pickup - 4WD

Bob, Auto Tech
Category: Chevy
Satisfied Customers: 4087
Experience: Plus 40 years GM, over 30 certified with Chevrolet, ASE certified Master Tech. (Expired, Retired)
Bob and 2 other Chevy Specialists are ready to help you
Expert:  Bob replied 7 years ago.
System must be slow today, just saw the bonus. Thank you very, very much.
Customer: replied 7 years ago.
Reply to Bob's Post: I been thinking that the heater core might not be the problem. I' ll tell you the problem is i' ve been losing heat for the last two years and that i flushed the system this year. the temp gets to 195 degrees and stays there. i was wondering if any of the actuators might be bad. I could go down the road and get heat but as soon as i slowed down or stopped the heat would get cool or cold. what else do you have as possibilities for the problem. All the hoses get hot, also. could it be the controls?
Expert:  Bob replied 7 years ago.
If the core is still connected, run the motor until it is up to operating temperature and then feel the heater hoses at the firewall. They both need to be good and hot. If they are not hot and equal, the core is restricted. This is the most common cause on your truck. It is possible to have a mode door problem but it will be hard to test the system with the dash out. Plus it is an automatic AC and requires a class 2 scan tool to run function tests on the mode doors and control panel. Let me know where your at and what you find.
Customer: replied 7 years ago.
I didn' t know what you meant, but i think i have manual ac.
Expert:  Bob replied 7 years ago.
If it has a cable control from the control panel to the heater control doors, it is manual. If it has electric motors or a control on the dash that is marked in degrees, it is automatic. The get tested in a similar way. First make sure the heater hoses get hot, both of them. If you move the temp control lever and can see or hear the mode door for heat open, that eliminates the door as a possible cause.
Customer: replied 7 years ago.
thanks a lot i appreciate all the help. i will just change the core then check. if that is not it i will be back. i didn' t think getting the dash out was that bad so i'll take my chances with the core. thanks again
Expert:  Bob replied 7 years ago.
Good chance that is the problem, but I will be here later if you need me. Good luck.

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
< Last | Next >
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
 
 
 

Meet The Experts:

 
 
 
  • Tim's Auto Repair

    mechanic

    Satisfied Customers:

    7641
    Have owned a repair shop for 25 yrs.
< Last | Next >
  • http://ww2.justanswer.com/uploads/TI/tim37857/2011-10-28_23053_S6301814.64x64.JPG Tim's Auto Repair's Avatar

    Tim's Auto Repair

    mechanic

    Satisfied Customers:

    7641
    Have owned a repair shop for 25 yrs.
  • http://ww2.justanswer.com/uploads/DT/dt69nova/2012-6-15_234154_pic1.64x64.jpg Dave Nova's Avatar

    Dave Nova

    Chevrolet Technician

    Satisfied Customers:

    6870
    ASE Master Certification. GM World Class Certification
  • http://ww2.justanswer.com/uploads/ggrote1/2009-06-27_031011_me.jpg Gary's Avatar

    Gary

    Chevy Technician

    Satisfied Customers:

    5404
    15 years GM master tech
  • http://ww2.justanswer.com/uploads/testedtuff/2009-09-26_170108_pictures.jpg John's Avatar

    John

    Master A.S.E Automotive technician

    Satisfied Customers:

    4071
    A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician
  • http://ww2.justanswer.com/uploads/RO/rodcuda/2011-7-25_224114_Donhoff1.64x64.JPG Neal's Avatar

    Neal

    Chevy Mechanic

    Satisfied Customers:

    2306
    Shop Owner and Mechanic on multiple makes.
  • http://ww2.justanswer.com/uploads/goodwrench9124/2008-11-09_220838_dscf0007.jpg goodwrench9124's Avatar

    goodwrench9124

    ASE Certified Technician

    Satisfied Customers:

    2041
    Ase Master Certified, GM Master Certified Tech. Awarded GM Top performer, Hybrid certified
  • http://ww2.justanswer.com/uploads/DR/drivefast1971/2012-1-12_172422_0009051tQKh.64x64.jpg Ron Z.'s Avatar

    Ron Z.

    - Chevy Tech -

    Satisfied Customers:

    1912
    18+yrs experience. State Inspector and Chevy Diagnostics