Question about 1999 GMC Suburban

1 Answer

Heater vent blows air when driving and blower is turned off.

Posted by on


1 Answer

  • Level 1:

    An expert who has achieved level 1.


    An expert that hasĀ over 10 points.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 10 Answers

This happens on vehicles that are a few years old you just have to deal with it.

Posted on May 03, 2013


6 Suggested Answers

  • 2 Answers

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

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.

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

  • 2 Answers

SOURCE: heeter is blowing cold air

Okay... First off I am no pro on fixing cars, but I did have this same problem. What I had to do is drain the radiator completely, then use prestone radiator flush to totally clean out the radiator. Once this is done go ahead and refill it with fresh radiator fluid. ONE BIG THING.... Do not replace it with DEXCOOL! This is a reddish orange color coolant, and is what caused you and me the problem to begin with. Make sure you use green coolant and mix it 50/50 or buy the premixed stuff. Like I said, I am no pro so I had to look up exactly how to do this. It took me around an hour and a half. Here are the instructions I used. Hopefully this helps. E-mail me at and tell me if this worked for you as it did for me!

Posted on Dec 16, 2008

  • 239 Answers

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

you have a vacuum leak

Posted on Jan 07, 2009

  • 2920 Answers

SOURCE: 2002 GMC Yukon blows cold air from the front, rear works fine

check you antifreeze level and make sure its full

Posted on Jan 26, 2009

  • 1 Answer

SOURCE: Dash vents will not blow air. Defroster and floor vents blow fine.

Is it a new vehicle? I had a new vehicle that had the same problem. Answer was that the holes weren't punched out of the vent.

Posted on May 23, 2009

Add Your Answer

Uploading: 0%


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



Related Questions:

1 Answer

A friend replaced my Heater Core for me and it still does Not blow Hot Air ...can you give me some trouble shooting ideas to check ?

Does the heater blower motor work? That is what blows cool air across and around the heater core and then through the case and out the vents as warm air blowing. The heater motor wiring circuit is separate, and gets pretty complicated with electronic HVAC controls, but it does have fuses.
If the blower motor works but you only get cold air, not warm, out the vents, then you have a problem with the heater case doors not operating properly. yes, the old temperature blend door problem, the actuator motors or the vacuum servos not operating the doors. By the time you get all that figured out and working again, you will be an HVAC expert in your own right. Your turn for a comment...what model and year of car anyway, are we talking about?

Feb 21, 2016 | Cars & Trucks

1 Answer

I have a 2000 gmc jimmy, everytime i start it up after a snowfall and turn on the heater snow blows out of all my heater vents

the heater blower gets the air from a chamber at the bottom of the windscreen and this area would be full of snow so I would expect that some snow would be drawn into the car on start up of the blower. Try changing the vent setting to car recirculation so that the car air is used and not outside air.

Jan 03, 2014 | Cars & Trucks

1 Answer

Heater not blowing hot air

when you operates the heater button worm water of your engine's water jackets enter to the evaporator locates inside your A/C blower & air flows through it & air becoming worm. Therefore I proposed you to check your vent linkages for vent doors inside the blower unit.

Nov 24, 2013 | Land Rover Range Rover Cars & Trucks

1 Answer

Heater and Defroster not blowing air

check vent flaps inside the blower unit....

Nov 24, 2013 | 1996 Mitsubishi Mirage

1 Answer

My 2003 Camry vents are not blowing any air no matter what speed or tempature. But when I turn the defrost on a slight bit of a/c or heat (depending what I set it on) comes through. But the little bit of...

Can you hear the blower motor running ?
Could be a dirty cabin air filter, or blower problem, or blend door problem. The blend doors direct air thru the heater core and evaporator core as well as the vents.
If you have not replaced the cabin air filter check your owners manual on how to check it.

Aug 06, 2012 | Cars & Trucks

1 Answer

2005 Grand Prix heater works fine when blower is off-air coming thru vent gets hot; once blower is turned on air turns cold. Why?

Sounds like a clogged heater core- insufficient coolant circulating through heater core, and as soon as you blow air past the core, it get cooled off.

Jan 09, 2010 | 2005 Pontiac Grand Prix

1 Answer

A/C and Heater will not blow air..

Blower motor resistor is most common ($20-$70) it controls the blower motor fan and speeds or fan relay fuse (usually under the hood) If it's not either then the blower itself is bad. You can pull the motor and apply 12volts to it to test, if it spins then the resistor.

Oct 02, 2009 | 2001 GMC Sierra Crew Cab

3 Answers

Blower runs but no air out the vents

You may have some debris blocking the passage of the vents. You may want to open the dashboard to investigate further. The blower motor may be running but it may not be driving the actual fan.

Jul 07, 2009 | 2001 Jeep Grand Cherokee

2 Answers

Heater/AC won't blow out air

blower motor is behind the glove box. also check the blower resistor it should be nex to the blower motor

Oct 02, 2008 | 1995 Mercury Tracer

Not finding what you are looking for?
1999 GMC Suburban Logo

Related Topics:

16 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts


Level 3 Expert

76164 Answers


Level 3 Expert

1311 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

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

Answer questions

Manuals & User Guides