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 sprinkles08 Your Own Question
sprinkles08
sprinkles08, ASE Certified Technician
Category: Chevy
Satisfied Customers: 21602
Experience:  ASE Master and Advanced level certified. Factory trained with 15 years dealership experience
9825021
Type Your Chevy Question Here...
sprinkles08 is online now
A new question is answered every 9 seconds

2011 Chevrolet suburban Air conditioning fan will not kick

Customer Question

2011 Chevrolet suburban Air conditioning hi fan will not kick on.
Submitted: 3 months ago.
Category: Chevy
Expert:  K. Wiggins replied 3 months ago.

Hello, does it have auto climate control?

Customer: replied 3 months ago.
it does
Customer: replied 3 months ago.
The fan works when I manually set the relay. Also I have 2 powers 1 ground and a low voltage at the relay connection. Don't know if that helps any
Expert:  Gary replied 3 months ago.

I am sorry for the long wait

which relay are you setting or testing at ?

Customer: replied 3 months ago.
Top left of you are standing behind the driver side fender
Expert:  Gary replied 3 months ago.

which relay ? what is it called ?

Customer: replied 3 months ago.
Hi fan relay
Expert:  Gary replied 3 months ago.

that relay when the fan should be on high should show 2 powers and 1 good ground then the last terminal only showing a ground when the fan should be on high speed

Customer: replied 3 months ago.
I found 2 powers 1 ground and a low voltage.
Expert:  Gary replied 3 months ago.

the ground will it come and go when the fan should be on high then off high speed ? or stay the same low voltage all the time ?

will the ground come and go when its off high speed then on high speed?

Customer: replied 3 months ago.
Sorry but I am a little confused
Expert:  Gary replied 3 months ago.

the leg with low voltage is our problem but we need to find out of that is supposed to be the ground all the time or the ground that the computer is supposed to turn on and off to turn the high relay on

Customer: replied 3 months ago.
I did a continuity test to the ground from the computer (thick black with white stripe) to the ground post on the block. All was good.
Expert:  sprinkles08 replied 3 months ago.

Hello and welcome to JustAnswer!

I'm not 100% sure what you're testing. You mentioned having automatic temperature control, in which case the blower motor is supplied power and ground by the blower motor controller based on a signal from the control head.

Can you post the VIN?

Do you truly have automatic temperature control or is it a manual system?

You mentioned 'air conditioning high fan' which I take to mean the blower motor. Are you dealing with a blower motor issue or the engine cooling fan?

Customer: replied 3 months ago.
Engine cooling fan
Expert:  sprinkles08 replied 3 months ago.

What actual symptoms are you trying to repair?

Customer: replied 3 months ago.
The hi fan won't turn on. With manifold gauges the red side pins and the high pressure relief valves opens. Once I manually set the relay the fan kicks on and the Ac works 100%
Expert:  sprinkles08 replied 3 months ago.

Do you have a scan tool to monitor data?

Customer: replied 3 months ago.
No sir.
Customer: replied 3 months ago.
When I apply a ground to the low voltage it trips the hi fan.
Customer: replied 3 months ago.
What sends the ground signal to the relay?
Expert:  sprinkles08 replied 3 months ago.

The engine controller turns the relay on when a/c high side pressure is high enough. You need to be able to monitor high side pressure and/or perform a relay actuator test to see if the driver is functional or if the fan isn't being commanded on.

Customer: replied 3 months ago.
Is there a cheap counter I can get to do that?
Expert:  sprinkles08 replied 3 months ago.

An entry level scan tool starts at about $2,000. If you aren't able to borrow one you may be able to rent one at a big chain parts store such as Autozone. Otherwise you can resort to replacing parts in hopes that takes care of it or allow a shop to diagnose the problem and then repair it yourself, which would most likely be .5 o 1 hour of labor.

Customer: replied 3 months ago.
Let me see what type of computer I can get. I will keep you posted.
Expert:  sprinkles08 replied 3 months ago.

Great!

Customer: replied 3 months ago.
I'm going to grab a computer from my corporate mechanical facility.
Expert:  sprinkles08 replied 3 months ago.
Great!
Customer: replied 3 months ago.
here is he update. I can't get my hands on the computer like I thought I could. I am trying to see if I could get one but j think I might just have to take it to the dealer.
Expert:  sprinkles08 replied 3 months ago.

You may be able to have a dealer diagnose it for .5 to 1 hour of labor and then do the work yourself.