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 carguyjosh Your Own Question

carguyjosh
carguyjosh, ASE Certified Technician
Category: Chevy
Satisfied Customers: 2172
Experience:  ASE certified , 16 yrs in field
12326834
Type Your Chevy Question Here...
carguyjosh is online now
A new question is answered every 9 seconds

1998 Chevy: blow..fuses..the compressor clutch ... Would you

Customer Question

1998 Chevy K1500 Silverado
Heater fan will not blow .. fuses are good .. so is the relay and because the fan won't turn on even though the light turns on when you push the A/C button it does not engauge the compressor clutch ... Would you suspect the dash control unit?
Submitted: 4 years ago.
Category: Chevy
Expert:  carguyjosh replied 4 years ago.
Good morning.

I would not suspect that the control unit in the dashboard is failing.
The most common cause of a blower motor failure on these trucks is a failing blower motor resistor.

Please let me know if you have a test light or multimeter and I can give you the diagnostic steps to find the source of the problem.

Thanks, Carguyjosh
Customer: replied 4 years ago.
Yes Have both but prefer multimeter.
Expert:  carguyjosh replied 4 years ago.

Okay well lets start testing.
The first thing I would like to have you do is test to verify that the fuse in the underhood relay box is good.

If the fuse is indeed good, I would like you to get to the blower motor. You'll find the blower motor under a trim panel above the passenger seat.
Disconnect the two wire connector and connector multimeter to both wires.
With the key in the on position, check to see if the blower motor has 12 V. If the motor has volts being supplied to it, the motor is at fault.

If the motor does not have 12 V. We will need to gain access to the heater control resistor.
To get access to the resistor if memory serves you will need to pull the glove box. The resistor sits on top of the heater box.
You will find that the blower motor resistor has four wires plugged into it. The wire colors are dark blue, light blue, tan, and yellow.
With the resistor unplugged, key in the on position, turn your blower fan switch onto speed one. Check for power on the yellow wire at the resistor.
If you have power at the yellow wire at the resistor, the fan speed switch is sending signal and we will assume it's good and can at least make the fan run on one speed.

You will find next to the resistor a blower control relay.
With the key in the on position, blower speed set to the first speed I would like you to test for power on the dark blue wire going into the relay.

If you have power on the dark blue wire I would like you to test for power coming out of the relay on the purple wire.

If you find that you have power going into the relay on the dark blue wire but no power coming out on the purple wire, the relay is failed.

Please let me know what you're testing reveals, and I will get back to you as quickly as possible with further answers.
I am at work from 7 AM to 5 PM but do carry a Blackberry so will getyour response as soon as you send it and get back to you as quickly as possible.

Thanks, Josh

carguyjosh, ASE Certified Technician
Category: Chevy
Satisfied Customers: 2172
Experience: ASE certified , 16 yrs in field
carguyjosh and 5 other Chevy Specialists are ready to help you
Customer: replied 4 years ago.
Thank You Thank You ..... I will preform these tests just as soon as it get light here .... and get back with you ....
Customer: replied 4 years ago.
Boy what an easy fix. Once I got under the Dash and over to the Blower Motor. Turns out the purple wire (12 Volts) going to the Blower Motor was loose enough that it had gotten HOT due to increased resistance. Cleaned it up ...Tightened it up with needle nose pliers and BINGO ... Fan works at all speeds and the A/C Compressor cycles now like it's supposed to. Thanks for aiming me in the right direction. I was about to order a controller
Expert:  carguyjosh replied 4 years ago.

Well I'm glad to hear it was such a simple fix.
It's nice when it works out that way..

 

have a great week. Thanks, Josh

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