Question about 2004 GMC Sierra

1 Answer

Heater only works on heat won't switch over to defroster or vents

Posted by on

1 Answer

  • Level 1:

    An expert who has achieved level 1.

    Mayor:

    An expert whose answer got voted for 2 times.

  • Contributor
  • 2 Answers

Sounds like the blend door. The actuator motor is located on top of the box (behind the glove box) and is notorious for failing.

Posted on Oct 26, 2012

6 Suggested Answers

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

SOURCE: heater blower does not come out vents

i had the same issue and it was the vacuum hose that goes over the alternator to the ac unit

Posted on Oct 30, 2008

picatudo
  • 239 Answers

SOURCE: 2001 gmc jimmy defroster-heater blower will not direct heat

you have a vacuum leak

Posted on Jan 07, 2009

  • 6 Answers

SOURCE: heater blower not working on 2005 Envoy

the blower is on a different fuse than the heat deforst one if the resistor is faulty the fan would run on speed 5 only so still could be fuse or motor check for power to main motor under glove box ??

Posted on Feb 04, 2009

  • 8 Answers

SOURCE: window defrost

it all has to do with vacums basically, when you turn the switch to defrost there is a hose that should **** a "door" so to speak over lettin the air travel through your defrost vents, and if your not gettin suction the in aint gonna switch over, and are you gettin it out of the floor vents?

Posted on Feb 11, 2009

alicantecoli
  • 22095 Answers

SOURCE: a/c and heater only blow air out of defrost

either a vacumn pipe is broken or the ends split so its not passing a vacumn to open the flaps,where they are and how to get to them i cant help because i have never worked on one as they are not here in spain.check the engine end first though .Look for some small rubber pipes running from the inlet manifold

Posted on May 30, 2009

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

2005 Honda Accord Ex (4 Cyl.) - Heater Vent to Floor doesnt seem to work


You need to look under the dash there are plastic pipes going to those vents sounds like they are not properly connected

Jan 06, 2014 | Cars & Trucks

1 Answer

2007 DODGE durango heater control


HAVC Vent Door/Motor problem
Need a service manual or repair shop

Jul 24, 2013 | Cars & Trucks

2 Answers

How to remove &install vent control switch


there is 3 blend door motors on a jeep,and the dash has to be pulled

Jan 27, 2013 | 1996 Jeep Grand Cherokee

1 Answer

Heater & defroster works fine but inside car windows keep fogging


So you have the vent settings to blow out of the windshield vents and still have fogging?

You can dry out the air more quickly if you use the air conditioner setting. It sounds backwards, but this is exactly what the manual in my older car said to do. (Some cars are electronic control and won't let you do this however - or they do it automatically with the defrost vent settings).

For the older car, I would set the heat to the hottest setting and press in the a/c button. The a/c dries out the air, but it does not have to be set to run cold.

Another thing that could help is to make sure that you do not have the vents set for "recycling" the air. The picture should look like a u shapped arrow. Make sure it is not pressed in.

Dec 20, 2011 | 1999 Oldsmobile Alero

1 Answer

I have steam coming out of my defroster & it smells like antifreeze without the defroster or heater even being on. What could this be? I am unable to see to drive because of a film that covers the...


yOUR HEATER CORE NEEDS TO BE REPLACED. ANTIFREEZE CONTINUALLY RUNS THROUGH YOUR HEATER CORE WITH OR WITHOUT THE HEAT OR AC BEING ON. THIS ALLOWS YOUR ANTI-FREEZE TO COOL ABIT WHEN IT RETURNS TO THE BLOCK.

Oct 15, 2011 | 1997 Pontiac Bonneville

1 Answer

On my sons 2000 chevy silverado 4.8 liter....the heater works fine....but when i switch control to defrost....only cold air blows out defrost vents....any help would be appreciated.


the heater & defroster baffles are controlled by electic motors that open and close the baffle (doors) to let the air to the heater and defroster vents. the motor must be bad

Jan 12, 2010 | 2001 Chevrolet Silverado

2 Answers

98 Jimmy throws out heat but won't switch to all vent options


Your going to have to replace the switch. The switch it self may have gone bad, since it works on a vacuum. It's common for the diaphragm in the switch assembly to go bad, if it's not the switch. Then it's going to be a bad actuator door and will need to be freed up. I have found it to be the switch it self get dirty and the vacuum needed to activate the actuator door is not there.

Good luck and keep me posted. When you turn the switch from defrost to heater, do you hear a air leak??? If you do then it's a good chance that it's the switch it self.

Dec 03, 2009 | 1998 GMC Jimmy

Not finding what you are looking for?
2004 GMC Sierra Logo

391 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts

yadayada
yadayada

Level 3 Expert

74945 Answers

Freddy

Level 3 Expert

1311 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22095 Answers

Are you a GMC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...