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 Hammer Time Your Own Question
Hammer Time
Hammer Time, L1 Master Technician
Category: Car
Satisfied Customers: 4942
Experience:  ASE Mastertech with Adv level Engine performance cert.
201885
Type Your Car Question Here...
Hammer Time is online now
A new question is answered every 9 seconds

rear air in conv. van not working. no blower either.

This answer was rated:

rear air in conv. van not working. no blower either. fan blower had previously been somewhat noisy but only a small nuisance. now nothing at all. there is a speed selector switch that i can't get a voltage at. think i have checked fuses but not sure where a relay could be hiding. would compressor run without pwr to blower mtr?
Your rear A/C is simply a branchh of the main air conditioner. If you are getting cold air from the front unit, the compressor is operating. The rear may be getting cold also but without a blower motor, you won't be able to tell. Since you had a noise in the unit previously, I suspect the blower motor was going bad leading up to this. I would first access the rear blower motor and use a testlight to determine if you are getting power and ground to it. If you are, then the motor just failed. It's also possible that the excess current draw from the noisey motor could have overloaded one of the switches or fuses.
Customer: replied 11 years ago.
Reply to Hammer Time's Post: there is no voltage at the 3 pin connector that plugs into the blower motor. I traced the 3 wires to what looks like 3 seperate relays just above the mtr housing. i have voltage at them but not through them. what triggers these relays, if that is what they are? Is there a compressor in the rear of my van, i thought there was, or does everything work off the one in the front?

You'll have to give me specifics on the make, model year and engine size before i can see if there is a schematic available for that but as a rule, the way they are wired is there is a front blower switch for the rear that can either control the rear or forward control back to the rear switch. There is usually a blower resister in the rear unit that reduces the current to change the blower speeds on signal from the switch.


As I stated earlier, there is one main compressor for the system and the rear unit is simply a second evaporator and expansion valve running off the main unit. The only thing separate are the blower and heater controls within that unit. The refrigerant is running through it at all times when the main unit is running. The blower is the only thing you can shut off.

Customer: replied 11 years ago.
The van is a 1999 GMC Savana with 350. Geneva is the custom pkg, if that helps any. You are exactly right on the blower switches configurations. I believe the fan could have failed as you said, it probably needed to be replaced anyway, but with no pwr at the point of connection to the blower, could it have burnt something up on its way out? I have traced pwr back to those 3 relays(?) Wiring diagram would be helpful. Thanks

OK, here's a schematic for you. As you can see, the 2 relays are powered by 2 different fuses. The blower motor switch triggers the relays by supplying trigger ground which then sends the power through the resister and then on to the blower motor. I would suspect your problem is one of the fuses blown out. There is a main 30A fuse in the underhood center. The other is a 10A fuse in the inside box. This info should be able to solve the problem for you. I would appreciate you clicking on the accept button and leaving some positive feedback for me.


Hammer Time, L1 Master Technician
Category: Car
Satisfied Customers: 4942
Experience: ASE Mastertech with Adv level Engine performance cert.
Hammer Time and 6 other Car Specialists are ready to help you
Customer: replied 11 years ago.
Excellent working with you, Hammer Time. found a single fuse blown that i still cant find on the schematic, but replacing it made the fan come on. I dont know how to give positive feedback to you other than this, but great help! thanks

Thank you, XXXXX XXXXX was able 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:

 
 
 
  • 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
< Previous | Next >
  • 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
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles Walnut Creek, CA
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
    Sue Charleston, WV
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff. Jim Castleberry, FL
  • Excellent reply, and also very quick. Really sounds like the Expert knows what he is talking about. I will be back to use your service when I need more help with my RV. Dutch USA
 
 
 

Meet The Experts:

 
 
 
  • Chris (aka-Moose)

    Chris (aka-Moose)

    Technician

    Satisfied Customers:

    1006
    16 years of experience
< Last | Next >
  • http://ww2.justanswer.com/uploads/MU/muddyford/2012-6-13_1204_1.64x64.png Chris (aka-Moose)'s Avatar

    Chris (aka-Moose)

    Technician

    Satisfied Customers:

    1006
    16 years of experience
  • http://ww2.justanswer.com/uploads/TE/TedG/2012-6-15_14759_avaLarge.64x64.jpg Ted G.'s Avatar

    Ted G.

    ASE Certified Technician

    Satisfied Customers:

    1694
    20 years auto repair experience, ASE Master Tech, Mechanical Failure consultant, Expert Witness
  • http://ww2.justanswer.com/uploads/joecamel90/2008-11-13_03615_head_shot.jpg George H.'s Avatar

    George H.

    ASE Certified Technician

    Satisfied Customers:

    1447
    ASE Master Tech 15+ yrs, AAS Automotive Technology, Factory trained Asian specialist
  • http://ww2.justanswer.com/uploads/BL/Bluegorilla/2012-6-21_16298_cam.64x64.JPG GM Tech (Cam)'s Avatar

    GM Tech (Cam)

    Auto Service Tech

    Satisfied Customers:

    669
    GM Grand Master Technician 2007. 14 years experience.
  • http://ww2.justanswer.com/uploads/AM/amedee/2013-10-24_23656_Amedee1.64x64.jpg Amedee's Avatar

    Amedee

    Former ASE Master Tech

    Satisfied Customers:

    2406
    ASE certified tech advanced level specialist. Wisconsin certified emissions state inspector
  • http://ww2.justanswer.com/uploads/SU/supermechanic/2013-8-23_03546_500.64x64.jpg Jerry's Avatar

    Jerry

    Master Mechanic

    Satisfied Customers:

    2123
    ASE master, 30+ years. All makes and models. Trouble shooter, shop forman, service manager
  • http://ww2.justanswer.com/uploads/CR/crzydrvr00/2013-11-3_12123_246347.64x64.jpg Richard's Avatar

    Richard

    ASE Certified Technician

    Satisfied Customers:

    992
    12 years Ford Lincoln/Mercury Jaguar dealership as a technician and shop foreman reparing all makes