Heater blower doesn't work

Tiny
HDLH883
  • MEMBER
  • 1995 GMC SIERRA
  • V8
  • 4WD
  • AUTOMATIC
  • 88,500 MILES
Heater blower quit working after stopping to fuel up. Blower was working fine before shutting the engine down. When restarted the engine the blower would not come on and radio display would not light and no signal (although volume control raised and lowered the static).
When I shut the engine off and restarted the radio worked again.
I checked the fuses and AC relay under the hood which are all good.
When I turn the fan switch on I hear a click behind the AC/heat control panel but no blower.
Do you
have the same problem?
Yes
No
Tuesday, January 5th, 2010 AT 10:23 PM

26 Replies

Tiny
RACEFAN966
  • EXPERT
Sounds like the controller may be bad

read the guide on testing wiring first, it will help

https://www.2carpros.com/articles/how-to-check-wiring

The wiring diagrams for you blower are attached below
Was this
answer
helpful?
Yes
No
+2
Wednesday, January 6th, 2010 AT 10:38 AM
Tiny
ROYHOBBS
  • MEMBER
  • 1997 GMC SIERRA
V8 four wheel drive automatic 180,000 miles.

No air coming out when fan switch is turned to any setting. Tried replacing the fuse (in cab) but did not work. Owner's manual says there is also a under hood blower fuse/relay which I have not replaced yet. Was working just fine yesterday and have had no problems with it before. Thanks for the assistance.
Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
BLUELIGHTNIN6
  • EXPERT
First check blower motor relay as your manual states. If okay then check your heater control switches. If they are okay as well then suspect faulty blower motor.
Was this
answer
helpful?
Yes
No
+6
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
ROYHOBBS
  • MEMBER
Thanks, I will try the other fuse but I currently do not have a service manual for this vehicle so not sure how to check the heater switches.
Was this
answer
helpful?
Yes
No
+1
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
BLUELIGHTNIN6
  • EXPERT
Your blower motor relay is located on top of the front A/C-heater blower housing, in dash.
Follow the link here to get an idea of how to test the blower motor relay.

http://www.2carpros.com/how_to/how_do_i_check_a_relay.htm
Was this
answer
helpful?
Yes
No
+6
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
ROYHOBBS
  • MEMBER
Thanks for the help, turned out to be the blower motor after all.
Was this
answer
helpful?
Yes
No
+2
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
ADUBBER
  • MEMBER
  • 1998 GMC SIERRA
Heater problem
1998 GMC Sierra V8 Four Wheel Drive Automatic

Hello I am sending anouther request on my vehicle
I have only the high setting on the fan motor

I have replaced the air actuator the heater relay the
control pannel on dash and the heater blower resitor as requested by you guys,

up until I replaced the heater relay I couldnt controll the temp it was on high always.

What next? I am so frustrated with this now.
There are two wires going into the motor one is purple and the other is black test light works on the purple on high only tried it on lowest settring 1st
I see 2 yellow wires in a harness thas is connected to something on the fire wall but no others

after looking further I found the yellow wire going into the resistor and on low it has no power going to it
Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
RASMATAZ
  • MEMBER
Hi adubber, Welcome to 2carpros and TY for the donation:

I want you to turn heater on set it at low and check for power at the yellow wire on the blower motor resistor let me know asap
Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
ADUBBER
  • MEMBER
I testerd for power on the yellow wire with the fan on low and found no power
Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
ADUBBER
  • MEMBER
Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
RASMATAZ
  • MEMBER
Replace the blower switch
Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
ADUBBER
  • MEMBER
What exactly are you refering to?
Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
ADUBBER
  • MEMBER
  • 1998 GMC SIERRA
  • V8
  • 4WD
  • AUTOMATIC
  • 11,500 MILES
Hello again,

I am the guy with the gmc sierra I replaced the controll console for the haeter and air cond- I replaced the relay for the fan I replaces the air door actuator, I replaced the heater blower resister
you asked me to test the yellow wire going into the resister with the fan set on low and I did this finding no power. What next?

I am will to pay more for the advise if needed.
Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
RASMATAZ
  • MEMBER
The switch is within the HVAC control module


http://www.2carpros.com/forum/automotive_pictures/12900_b1_9.jpg




http://www.2carpros.com/forum/automotive_pictures/12900_b2_9.jpg

Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
KHLOW2008
  • EXPERT
Hi adubber,

You should have replied to your previuos post so that whoever was attanding to you can get notification and attend to you as soon as he gets online.

This would keep the history of what had transpired to allow an easier understanding of the problem and recommendations and repairs carried out.

Please do not edit the post as no notifications would be sent out.

Let me know the following.

With blower control speed at Low, you have no power supply to the yellow wire. Let ma know the following.
1. Do you have power at the Tan wire when blower speed is set at M1?
2. Do you have power at the Light Blue wire when blower speed is set st M2?
3. Does applying battery voltage to the terminal of the resistor at the yellow wire work the blower at low speed?
4. Did you test the HTR fuse ( 25A) in the fuse box?

I will copy this thread to the previous one and we will work from there.
Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
ADUBBER
  • MEMBER
Thats odd the new console had the switch attached
could the new switch be bad? Or could there be some other problem?

UPDATED 1-19-10
Hi,

I ran a power line from the battery terminal to the yellow wire going into the resistor and the blower run on low, I did the same with the brown and it runs the fan on med and on blue it runs on med high
the high comes on if you turn it to high before starting the vehicle
i9f you have it on any other setting and start the vehicle it don't but will turn on after a few seconds or minutes no pattern.
I tested the 25A heater fuse and its good I found a aircond- relay in the fuse box under the hood and replaced it but that didn't change
I noticed that the air cond- don't come on at first when you push the button and after a while the light on the panel turns on.
Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
RASMATAZ
  • MEMBER
Earlier you said you don't have power at the yellow wire on the resistor-if the switch is working properly the yellow wire should power up on the low position.
Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
KHLOW2008
  • EXPERT
Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
ADUBBER
  • MEMBER
Hi,

I ran a power line from the battery terminal to the yellow wire going into the resistor and the blower run on low, I did the same with the brown and it runs the fan on med and on blue it runs on med high
the high comes on if you turn it to high before starting the vehicle
i9f you have it on any other setting and start the vehicle it don't but will turn on after a few seconds or minutes no pattern.
I tested the 25A heater fuse and its good I found a aircond- relay in the fuse box under the hood and replaced it but that didn't change
I noticed that the air cond- don't come on at first when you push the button and after a while the light on the panel turns on.

From: "forum@2carpros. Com"
Sent: Sun, January 17, 2010 1:56:14 AM
Subject: Topic Reply Notification - 1998 GMC Sierra heater blower resister
Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)
Tiny
ADUBBER
  • MEMBER
[/quote:fda5d37c28]

Hi,

I ran a power line from the battery terminal to the yellow wire going into the resistor and the blower run on low, I did the same with the brown and it runs the fan on med and on blue it runs on med high
the high comes on if you turn it to high before starting the vehicle
i9f you have it on any other setting and start the vehicle it don't but will turn on after a few seconds or minutes no pattern.
I tested the 25A heater fuse and its good I found a aircond- relay in the fuse box under the hood and replaced it but that didn't change
I noticed that the air cond- don't come on at first when you push the button and after a while the light on the panel turns on.

From: "forum@2carpros.com"
Sent: Sun, January 17, 2010 1:56:14 AM
Subject: Topic Reply Notification - 1998 GMC Sierra heater blower resister

Hello,

You are receiving this email because there is a reply to your question, "1998 GMC Sierra heater blower resister" at Auto Repair Car Questions.

To view and follow-up on the reply to your question, please click on the following link, http://www.2carpros.com/forum/viewtopic.php?p=772779#772779

Sincerely,

Bob, Ken and all of the 2CarPros team.
Was this
answer
helpful?
Yes
No
Saturday, November 17th, 2018 AT 9:41 AM (Merged)

Please login or register to post a reply.

Recommended Guides