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 RJAuto11 Your Own Question

RJAuto11
RJAuto11, ASE Certified Technician
Category: Dodge
Satisfied Customers: 126
Experience:  ASE Master Tech working on Chryslers 14+ Years
27212359
Type Your Dodge Question Here...
RJAuto11 is online now
A new question is answered every 9 seconds

1999 dodge: 4wd..v8..Engine temp normal, fan works

Customer Question

1999 dodge ram 4wd 360 v8. Heat temperature control inoperative. Engine temp normal, fan works normal, duct settings normal. What do I check and how do I access the components for checking.
Submitted: 4 years ago.
Category: Dodge
Expert:  RJAuto11 replied 4 years ago.

That year ram has a blend door actuator, that controls the door for blending hot and cold air in the HVAC box, the servo motor must be accessed by removal of the heater-a/c housing.

 

Expert:  RJAuto11 replied 4 years ago.

1.Disconnect the battery negative cable.

2. Remove the instrument panel from the vehicle, I have found that this step, you can tie up the passengers side to the grab handle and place fender covers over the 4x4 shifter and not have to remove the entire dash.

3. remove the heater-a/c housing from the truck.

4.unplug the wire harness from the servo motor.

and remover its 2 mounting screws that secure it to the housing.

and remove the actuator.

Customer: replied 4 years ago.
I don't quite understand the instructions. What do I have to tie up? Is there a way to test the component before removing the dash? Could it be a vacuum problem? It has been very cold here and the truck is outdoors. Can I temporarily block the cold air intake until better weather? If there is a way to block the air intake and that resolves the problem temporarily then that would tend to support the blend door malfunction too.
Expert:  RJAuto11 replied 4 years ago.
I am sorry I was not able to help you.
Customer: replied 4 years ago.
Relist: Answer quality.
What is the best way to proceed in diagnosing the problem. There are several possibilities. I would like to take the least destructive first. I will attempt to establish coolant flow through the heater. If it is good I will need to check for vacuum at the heater conrol panel and at the servo. Lastly and most difficult is to check the servo visually. I expected a thorough answer but the expert jumped to extracting the servo. The procedure he prescribed was a bit ambiguous too.
Expert:  RJAuto11 replied 4 years ago.

This is the diagram for your trucks HVAC system heater control.

  • graphic

This is the diagnostic tree from the service repair book for your Dodge ram.

 

graphic

 

This is the duct flow air chart for your HVAC box that is used in your ram truck.

 

graphic

 

graphic

You have told me that all of your mode doors work ok , so that leads me to think that the operation of your blend air door is the root cause of your heater malfunction. Use the wiring chart I have provided to test for voltages and grounds, If its not in your electrical wiring , and your switch is working correctly, the chances are , either your blend air servo motor is binding up or is defective, or your door in your HVAC box may be bound up or broken. Possibly some foreign matter has gotten into your air box and bound it up or the door hinge point may have snapped. --------------------

 

 

This is where your truck taps into the engine to supply your HVAC mode switch with the needed engine vacuum to operate the other none electrical servos in your HVAC box.

 

graphic

 

Under your windshield cowling, is the location of your vacuum reservoir, to supply vacuum even when your engine is under heavy load and producing low manifold vacuum. But your mode doors are working fine, so I think this part of your system is not the cause of your problem.

 

 

The Possible causes listed in the factory manual for heater outlet air temperature being unadjustable are as follows.

1. A faulty heater-A/C control.

2. A faulty blend-air door servo.

3. A faulty, obstructed or improperly installed blend door.

4. An obstructed cowl air intake.

5. The engine cooling system.

 

This is the exact info I have available to me on your Dodge ram , I hope this helps you to track down the source of your problem.

Please let me know if I can help you in any way to further diagnose this problem with your vehicle.

 

RJAuto11, ASE Certified Technician
Category: Dodge
Satisfied Customers: 126
Experience: ASE Master Tech working on Chryslers 14+ Years
RJAuto11 and 8 other Dodge Specialists are ready to help you
Customer: replied 4 years ago.
I've started working the problem and I noticed something new. The a/c compressor comes on every 6-7 seconds and runs for 1-2 seconds. The climate control settings are defrost, fan low, temp = max hot. Is this an electrical or sensor malfunction that is causing my no heat problem?
Expert:  RJAuto11 replied 4 years ago.
The compressor is kicking on to remove moisture and is normal.
Customer: replied 4 years ago.
The problem is fixed. I flushed the heater and it worked for a few hours and then quit. I consulted a local Dodge mechanic and he spoke of a propensity for this system to develop an air lock. We added antifreeze through the radiator and expansion bottle. All is well. Thanks.
Expert:  RJAuto11 replied 4 years ago.
Thank You for using Just Answer.

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 AM VERY GLAD THAT I TOOK A CHANCE ON YOUR PROBLEM SOLVING SKILLS. I WAS SUCCESSFUL IN REPLACING THE FUEL PUMP. MY TRUCK RUNS LIKE A CLOCK. IT RUNS LIKE THE DAY I BOUGHT IT. NO LUNGING FORWARD, THE TURBO REACTS THE SECOND I STOMP ON THE GAS, AND IT HAS A LOT MORE POWER AND EVEN SOUNDS BETTER TO ME. IT SAVED ABOUT $500.00 BY DOING THE WORK MYSELF. I GIVE YOU ALL THE CREDIT FOR YOUR DIAGNOSING THE PROBLEM, JUST FROM THE SYMPTONS I GAVE YOU OVER THE e MAIL. I WILL USE YOUR WEB SITE AGAIN AND REFER MY FRIENDS. THANKS SO MUCH FOR THE HELP. TOM WHITTAKER USA
< Last | Next >
  • I AM VERY GLAD THAT I TOOK A CHANCE ON YOUR PROBLEM SOLVING SKILLS. I WAS SUCCESSFUL IN REPLACING THE FUEL PUMP. MY TRUCK RUNS LIKE A CLOCK. IT RUNS LIKE THE DAY I BOUGHT IT. NO LUNGING FORWARD, THE TURBO REACTS THE SECOND I STOMP ON THE GAS, AND IT HAS A LOT MORE POWER AND EVEN SOUNDS BETTER TO ME. IT SAVED ABOUT $500.00 BY DOING THE WORK MYSELF. I GIVE YOU ALL THE CREDIT FOR YOUR DIAGNOSING THE PROBLEM, JUST FROM THE SYMPTONS I GAVE YOU OVER THE e MAIL. I WILL USE YOUR WEB SITE AGAIN AND REFER MY FRIENDS. THANKS SO MUCH FOR THE HELP. TOM WHITTAKER USA
  • Just a quick line to tell you how pleased I am to have my brakes working properly after all this time. Your answer was what I needed. I would certainly recommend you highly. God bless! Rev. Jerry Baysinger Holts Summit, Mo
  • I recently asked a question about my 2005 dodge ram, and I just wanted to let my Expert know that he hit the nail squarely on the head with his answer. I wanted to thank him again. Greg Pittsburgh, PA
  • Just a quick line to tell you how pleased I am to have my brakes working properly after all this time. Your answer was what I needed. I would certainly recommend you highly. God bless! Jerry Holts Summit, MO
  • I was skeptical at first but thought I'd give it a try. I was pleasantly surprised. Your site actually is a quality service that I would recommend to others in a heartbeat. Stan Sayre, PA
  • 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
 
 
 

Meet The Experts:

 
 
 
  • Jerry

    Master Mechanic

    Satisfied Customers:

    1227
    ASE Master tech, 30 years exp. troubleshooter, driveability tech
< Last | Next >
  • http://ww2.justanswer.com/uploads/SU/supermechanic/2013-8-23_03546_500.64x64.jpg Jerry's Avatar

    Jerry

    Master Mechanic

    Satisfied Customers:

    1227
    ASE Master tech, 30 years exp. troubleshooter, driveability tech
  • http://ww2.justanswer.com/uploads/MO/MoparCertified/2012-6-7_4142_mechanic.64x64.jpg Mopar Certified's Avatar

    Mopar Certified

    Dodge Technician

    Satisfied Customers:

    5813
    24 Year Chrysler/Dodge Certified Specialist
  • http://ww2.justanswer.com/uploads/jeep10000/2008-9-18_222938_192601.jpg Chris's Avatar

    Chris

    Shop Foreman

    Satisfied Customers:

    4041
    ASE and Chrysler Certified Master Tech
  • http://ww2.justanswer.com/uploads/ke4ich/2009-08-12_212931_DSC02211.JPG moparfl's Avatar

    moparfl

    ASE Certified Technician

    Satisfied Customers:

    3285
    ASE Master Tech Gold level Chrysler Status 30 years dealership exp
  • http://ww2.justanswer.com/uploads/DO/dodgerench/2012-8-1_1142_IMG3173.64x64.JPG Dodgerench's Avatar

    Dodgerench

    ASE Certified Technician

    Satisfied Customers:

    2480
    30+ years Dodge/Chrysler exp., ASE Master with L1 certification. Driveability/ combustion specialist
  • http://ww2.justanswer.com/uploads/RO/rodcuda/2011-7-25_224114_Donhoff1.64x64.JPG Neal's Avatar

    Neal

    Dodge Mechanic

    Satisfied Customers:

    1870
    30 years experience in Dodge Chrysler and Plymouth
  • http://ww2.justanswer.com/uploads/tsmodie/2009-6-10_144056_tim.jpg Tim Mohr's Avatar

    Tim Mohr

    ASE MASTER TECH

    Satisfied Customers:

    1664
    30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL