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 Earl Your Own Question

Earl
Earl, Ford Technician
Category: Ford
Satisfied Customers: 727
Experience:  Senior Master Tech since 2006 Diesel certified, have been with Ford since 1995.
29257239
Type Your Ford Question Here...
Earl is online now
A new question is answered every 9 seconds

F550: cooling..only blows..defrost..the damper vacuum operated

Resolved Question:

F550, 2000 diesel
The heating and cooling only blows out the defroster. Is this a default setting for the damper that moves the air direction (defrost, face, feet) in case of a failure? Is the damper vacuum operated or electric? How can I test the components?
Thanks!
Tony
Submitted: 4 years ago.
Category: Ford
Expert:  Earl replied 4 years ago.
Chat Conversation Started
Earl Cowette :

Hello, Defrost is the default position when the system looses vacuum. The 7.3 diesel has a electric vacuum pump located on the passenger side of the engine compartment between the vacuum reservoir and the heater box. If you turn the key to the run position do you hear this pump run?

Customer:

I don't have the vehicle here. I did check the vacuum pump fuse and it is good. I will check it tomorrow but what would be the next step ?

Earl Cowette :

Yes, the vacuum pumps are pretty common to fail and cause this concern. When you get to the truck, if the pump does not run, disconnect the electrical connector to it and check for voltage using a volt meter if you have one or you can use a test light on the pin with the light blue and pink wire. You should have 12 volts with the key in the run position. If voltage is present the pump is most likely bad and will need to be replaced. After replacement turn the key to the run position and let is run for a minute or two and it should shut off once it builds enough vacuum. If the pump continuously runs and never shuts off then there is a leak in one of the vacuum lines and will need to be repaired or it will burn out the new pump.

Customer:

OK, thanks!

Earl Cowette :

Alright, let me know if there is anything else.

Customer:

can i keep this chat open until tomorrow until I check it out incase there is something else to ask you?

Earl Cowette :

Yes that's fine. I usually check a few times a day, so my response may not be immediate, but I will get back to you.

Customer:

ok no problem

Customer:

Earl,the vacuum pump is working. I checked the hoses and everything seemed fine. There are two fittings in the pump (black and white). The end of the white one is open so I put my finger over it and I could feel the vacuum then the pump shut off. Amazingly the climate control selector started working. Is there a check valve in that fitting that can be replaced? If it happens again....what is the fix? Thanks again.

Earl Cowette :

There is a check valve in that connection internal to the pump. The white end is supposed to be open, that is the exhaust side for the vacuum pump. Buy placing your finger over it, you may have allowed the check valve to reset. Unfortunately the vacuum pump is not serviceable and can only be replaced as a assembly.

Customer:

ok

Customer:

thanks for the help

Earl, Ford Technician
Category: Ford
Satisfied Customers: 727
Experience: Senior Master Tech since 2006 Diesel certified, have been with Ford since 1995.
Earl and other Ford Specialists are ready to help you

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:

 
 
 
  • AlvinC answered a question about my Ford truck that only someone with an in-depth knowledge of his subject would have known what was going on. Rich D USA
< Last | Next >
  • AlvinC answered a question about my Ford truck that only someone with an in-depth knowledge of his subject would have known what was going on. Rich D USA
  • Because of your expertise, you armed me with enough ammunition to win the battle with the dealer. They are installing a fuel filter and fuel pump at no charge to me. Molly USA
  • I needed help with my car on Saturday morning....got a response in 5 minutes, and it was the perfect solution. Thanks again to your service. Jason V. Kirkland, WA
  • I do know, after going though this with JustAnswer, that I can somewhat trust my mechanic but I will always contact you prior to going there. BR New Jersey
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P Elm City, NC
  • used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future. David L. Richmond, TX
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil Marysville, CA
 
 
 

Meet The Experts:

 
 
 
  • Ron

    ASE Certified Technician

    Satisfied Customers:

    20942
    23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
< Last | Next >
  • http://ww2.justanswer.com/uploads/FO/fordguy4u/2011-12-17_222940_HPIM1257.64x64.JPG Ron's Avatar

    Ron

    ASE Certified Technician

    Satisfied Customers:

    20942
    23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
  • http://ww2.justanswer.com/uploads/MU/muddyford/2012-6-13_1204_1.64x64.png Chris (aka- Moose)'s Avatar

    Chris (aka- Moose)

    Ford Technician

    Satisfied Customers:

    22382
    16 years experience with Ford.
  • http://ww2.justanswer.com/uploads/JM/jmcdo28/2012-2-23_01655_resized.64x64.jpg John Mc's Avatar

    John Mc

    Ford Technician

    Satisfied Customers:

    5493
    19 years Ford Lincoln Mercury experience
  • http://ww2.justanswer.com/uploads/wmarti7/2009-4-18_04332_Avatar.jpg Chuck's Avatar

    Chuck

    ASE Certified Technician

    Satisfied Customers:

    1684
    33 Years Experience,Ford Senior Master,ASE Master,L1 Advanced Engine Performance
  • http://ww2.justanswer.com/uploads/CR/crzydrvr00/2013-11-3_12123_246347.64x64.jpg Richard's Avatar

    Richard

    ASE Certified Technician

    Satisfied Customers:

    1518
    12 years at a Ford Lincoln/Mercury and Jaguar dealer as a technician and shop foreman.
  • http://ww2.justanswer.com/uploads/BA/baddad1/2014-4-1_23659_avatar.64x64.jpg Mike V.'s Avatar

    Mike V.

    Auto Service Technician

    Satisfied Customers:

    789
    25 years experience on all makes and models, Licensed NYS Inspector.
  • http://ww2.justanswer.com/uploads/lostrider/2009-9-26_23144_php4VNWAA_c1PM1.jpg lostrider's Avatar

    lostrider

    Ford Technician

    Satisfied Customers:

    2940
    ASE Master Technician, Ford Senior Master Technician,Diesel certified, ASE Master, 22 yrs FORD exp.
 
 
 
Chat Now With A Ford Mechanic
Earl
Earl
Technician
689 Satisfied Customers
Senior Master Tech since 2006 Diesel certified, have been with Ford since 1995.