1999 Jeep Wrangler Logo
Paul Steinke Posted on Dec 05, 2013

Heat not working on 99 Jeep Wrangler. Blows cold air in vent and defrost.

1 Answer

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  • Contributor 25 Answers
  • Posted on Dec 06, 2013
offroadlover
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You may want to check the two water houses that feed the heater core. they both have to be hot. (they are usually located next to the thermostat housing.) If they are cold first check the coolant level. Fill up if needed, then you may have to check of there is an obstruction by the housing or the heater core is clogged up. I would first disconnect the hoses and see inside the thermostat housing with a lamp. Also blow some Air inside the heater core to see if flushing is needed. Well if those hoses are both hot then that must be a problem inside the cabin with the vents selection. Either an electric switch or cable. But there are already a few things to check first.

5 Related Answers

Anonymous

  • 11896 Answers
  • Posted on Jul 01, 2009

SOURCE: Jeep AC blows cold air at defrost and feet but not through vents

There is a flap that directs the air. the flap is controlled by a vacuum actuator. This is located inside the venting. The actuator is connected to little vacuum hoses that attach to the temperature control switch. Either the flap is stuck, or the actuator has gone bad.

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Anonymous

  • 144 Answers
  • Posted on Jul 19, 2009

SOURCE: 2005 Wrangler X a/c only blows from defroster

Check under your hood for a loose or leaking vac line , The A/C system on your jeep uses manifold vac to move the air mix doors and with no vac the air mix door will move into the defrost position. Find your vac leak and that will fix your problem.

Anonymous

  • 1071 Answers
  • Posted on Aug 19, 2009

SOURCE: air conditioning stuck on vent

the mode door motor is bad

Anonymous

  • 1 Answer
  • Posted on Jan 13, 2010

SOURCE: Cold air passenger side, warm air driver's side

same thing happened to mine at 2 yrs. old , the connecting arm on air mix positioner broke. The whole dash had to come out. Part was cheap but labor was huge. This is not a job for the do-it-yourself.

Testimonial: "We have had to attend to this problem, and asyou have said the part cost was small and the labour huge. At least 8 hours to complete."

jackdouglass

  • 107 Answers
  • Posted on Sep 09, 2010

SOURCE: Air only blows from the dash vents and will not

the damper or flapper ibside the heater box is not moving. If they are vaccum actuated could be lack of vaccum or bad diafram in the actuator...replace

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Related Questions:

0helpful
1answer

2005 jeep wrangler blows warm air not cold

Well this is different since most questions now are about no heat.
If one ac line is cold and the other is warm, I would suspect a blend door under the dash is not working. The blend doors direct air thru the heater core and the vents.
1helpful
1answer

My heater does not blow in floor in a dodgeram 1500

the heater vacuum motor and lines needs to be checked.Also get the blend door checked.

NO HEAT ON FLOOR VENTS

---------

As per your problem mentioned. There are few solved help links to troubleshoot these problems. Go through the list and Click the link below:----

2000 Toyota Avalon: No heat on Passenger Side?

http://whatisbyme.blogspot.in/2012/05/2000-toyota-avalon-no-heat-on-passenger.html


------------

No heat on Oldsmobile Silhouette?


http://technoanswers.blogspot.in/2012/02/no-heat-on-oldsmobile-silhouette.html

------------

Heater blows cold?

http://schematicsdiagram.blogspot.in/2012/02/heater-blows-cold.html

-----------

Heat blows cold on drivers side and hot on passenger side?

http://schematicsdiagram.blogspot.com/2011/12/heat-blows-cold-on-drivers-side-and-hot.html

----------

Hot air on the driver's side vents only?

http://repairhelpcenter.blogspot.com/2012/01/hot-air-on-drivers-side-vents-only.html

--------------

Temperature gauge does not move and no heat when heater is ON?

http://technoanswers.blogspot.com/2012/01/temperature-gauge-does-not-move-and-no.html

-----------

1992 Toyota Camry: A/C Control light Flashing and A/C not Blowing Cold?

http://technoanswers.blogspot.in/2012/04/1992-toyota-camry-ac-control-light.html

--------------

No heat, blower blows only cold?

http://technoanswers.blogspot.in/2012/02/no-heatblower-blows-only-cold.html

----------

Ford F150 Ac only blows through defrost vents?

http://technoanswers.blogspot.com/2012/01/forf-f150-ac-only-blows-through-defrost.html

----------

Dodge A/C come out of defrost vents only?

http://technoanswers.blogspot.com/2012/01/dodge-ac-come-out-of-defrost-vents-only.html

---------

Ac vacuum line on dodge cummins?

http://technoanswers.blogspot.com/2012/01/ac-vacuum-line-on-dodge-cummins.html

---------

Ford ranger AC blows cold through defrost vents instead on cabin vents?

http://technoanswers.blogspot.com/2012/01/ford-ranger-ac-blows-cold-through.html

----------

2005 Chrysler PT Cruiser: A/C Blows Warm?

http://whoisbyme.blogspot.in/2012/06/2005-chrysler-p8t-cruiser-ac-blows-warm.html

-------------

2009 Mercury Grand Marquis: A/C blows Cold From Defrost Vent Only?

http://whoisbyme.blogspot.in/2012/06/2009-mercury-grand-marquis-ac-blows.html

-----------

AC not blowing through Vents on 2007 Chevy Trailblazer?

http://schematicsdiagram.blogspot.in/2012/04/ac-not-blowing-through-vents-on-2007.html

----------

Passenger side temperature is warm air out of dash vents?

http://schematicsdiagram.blogspot.in/2012/04/passenger-side-temperature-is-warm-air.html

----------


These will help.

Thanks.

0helpful
1answer

No heat from vents

As per your problem mentioned. There are few solved help links to troubleshoot these problems. Go through the list and Click the link below:----

2000 Toyota Avalon: No heat on Passenger Side?

http://whatisbyme.blogspot.in/2012/05/2000-toyota-avalon-no-heat-on-passenger.html

------------

No heat on Oldsmobile Silhouette?


http://technoanswers.blogspot.in/2012/02/no-heat-on-oldsmobile-silhouette.html

------------

Heater blows cold?

http://schematicsdiagram.blogspot.in/2012/02/heater-blows-cold.html

-----------

Heat blows cold on drivers side and hot on passenger side?

http://schematicsdiagram.blogspot.com/2011/12/heat-blows-cold-on-drivers-side-and-hot.html

----------

Hot air on the driver's side vents only?

http://repairhelpcenter.blogspot.com/2012/01/hot-air-on-drivers-side-vents-only.html

--------------

Temperature gauge does not move and no heat when heater is ON?

http://technoanswers.blogspot.com/2012/01/temperature-gauge-does-not-move-and-no.html

-----------

1992 Toyota Camry: A/C Control light Flashing and A/C not Blowing Cold?

http://technoanswers.blogspot.in/2012/04/1992-toyota-camry-ac-control-light.html

--------------


No heat, blower blows only cold?

http://technoanswers.blogspot.in/2012/02/no-heatblower-blows-only-cold.html
----------

Ford F150 Ac only blows through defrost vents?

http://technoanswers.blogspot.com/2012/01/forf-f150-ac-only-blows-through-defrost.html

----------

Dodge A/C come out of defrost vents only?

http://technoanswers.blogspot.com/2012/01/dodge-ac-come-out-of-defrost-vents-only.html

---------

Ac vacuum line on dodge cummins?

http://technoanswers.blogspot.com/2012/01/ac-vacuum-line-on-dodge-cummins.html

---------

Ford ranger AC blows cold through defrost vents instead on cabin vents?

http://technoanswers.blogspot.com/2012/01/ford-ranger-ac-blows-cold-through.html

----------

2005 Chrysler PT Cruiser: A/C Blows Warm?

http://whoisbyme.blogspot.in/2012/06/2005-chrysler-p8t-cruiser-ac-blows-warm.html


-------------

2009 Mercury Grand Marquis: A/C blows Cold From Defrost Vent Only?

http://whoisbyme.blogspot.in/2012/06/2009-mercury-grand-marquis-ac-blows.html

-----------

AC not blowing through Vents on 2007 Chevy Trailblazer?

http://schematicsdiagram.blogspot.in/2012/04/ac-not-blowing-through-vents-on-2007.html

----------

Passenger side temperature is warm air out of dash vents?

http://schematicsdiagram.blogspot.in/2012/04/passenger-side-temperature-is-warm-air.html

----------


These will help.

Thanks.

0helpful
1answer

My 2006 jeep Liberty Front Defrost blows cold air. When I turn on the heat every vent blow hot air, except the front defrost and it blows cool air...any suggestions?

Sounds like defrost door on heater box is not work You need to get under dash and check controls on the box. Good luck
0helpful
1answer

Air only blows from the dash vents and will not change to the defrost or floor, and I have no heat - only cold air. Air conditioning seems to work. 1994 jeep grand cherokee v8 with climate control.

the damper or flapper ibside the heater box is not moving. If they are vaccum actuated could be lack of vaccum or bad diafram in the actuator...replace
1helpful
1answer

Air conditioning stuck on vent

the mode door motor is bad
1helpful
1answer

When I turn my vent selector to defrost on the far right (air con off)the air conditioning comes on. The dash vents will blow ambient air, but defrost setting blows air con. Any ideas?

It's normal for the A/C compressor to come on with the defroster to dehumidify the air so the windsheild won't fog up under humid conditions. You can still control the air temp. out the vents with the temp. select switch.
2helpful
1answer

2005 Wrangler X a/c only blows from defroster

Check under your hood for a loose or leaking vac line , The A/C system on your jeep uses manifold vac to move the air mix doors and with no vac the air mix door will move into the defrost position. Find your vac leak and that will fix your problem.
9helpful
1answer

Jeep AC blows cold air at defrost and feet but not through vents

There is a flap that directs the air. the flap is controlled by a vacuum actuator. This is located inside the venting. The actuator is connected to little vacuum hoses that attach to the temperature control switch. Either the flap is stuck, or the actuator has gone bad.
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