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How to replace HVAC Control box on jeep wrangler with step by step process

The HVAC control box is located behind the dashboard of your wrangler controlled by knobs on the dashboard. It’s inaccessible unless you remove the panel housing the controls and the electrical harnesses. The three knobs control the temperature, fan speed, and where the air goes. In this article, we are going to see the step-by-step process to replace HVAC Control box on jeep wrangler

The HVAC control box is used to control all the features of the A/C system in your wrangler electronically. It has sensors that read data inside and outside your wrangler and uses the analyzed data to readjust the A/C system to keep the interior of your wrangler comfortable for both the driver and passengers.  

The HVAC control box rarely fails, and when you notice the A/C system is not working, you need to diagnose the cause. It could be due to: broken cooling fans, refrigerant leak, a faulty air compressor, a faulty condenser, or electrical problems that are either related to the HVAC control box or the rest of the A/C system.  

If all of these check out to be in good working condition, the HVAC box has an issue. The HVAC control box shows some signs when faulty or failing.  

What are the signs of a faulty or failing HVAC control box on jeep wrangler?

A faulty or failing HVAC control box can be very dangerous sometimes. You have to often then and now check for any signs of failing HVAC control box if you are a hardcore off-roading enthusiast.

As the dust and dirt getting into the vehicle may also lead to the failure of HVAC control box on jeep wrangler. Below are some of the most common signs of a faulty HVAC control box.

Uneven air distribution in the cabin. 

There are several vents in your wrangler’s cabin. The HVAC control box is responsible for directing air from the A/C system to the vents. If you notice that some parts of the cabin are warmer or colder than others, it means that a specific vent in that part is not blowing air or you might notice that the air does not reach specific vents when you change the settings on the controls. 

replace HVAC Control box in jeep wrangler

The HVAC box is a computerized electrical system for the A/C system. When the HVAC box’s software is out of date, you’ll have to update it. Manufactures issued updates for the wrangler’s HVAC box once in a few years, but if yours is faulty due to a software failure or has a bug, you’ll have to get it updated sooner than you expected 

Uneven heating and cooling.  

You may notice that you’re the A/C does not cool the cabin well enough as you want it to regardless of the controls you select and does not heat sufficient when you want it to. If the A/C system is in good working condition, the HVAC box needs a software update or a replacement unit.  

Fans are not running. The HVAC control box controls the fans that regulate the air temperature in your cabin. If there is an issue with the box, the fans will not work. The cold or hot air will blow lightly over the vents. The cabin will overheat or become cold according to the outside weather condition.  

AC compressor not coming on 

The air compressor is also powered and controlled by the HVAC box. It turns the air compressor on when turned on, thus blowing cold or hot hair depending on the temperature settings you’ve set. If it does not turn on or turn off after turning it on, the box has a problem.  

Some A/C parts might overheat.  

The HVAC controls the whole A/C system, and if you notice some parts of the A/C, such as the air compressor overheating more than others. You need to diagnose this as early as possible as overheating causes more damage to the A/C components. You’ll end up spending more than you had expected.  

replace HVAC Control box in jeep wrangler

If the control knobs on the control panel of the HVAC unit blink on and off for about 30 seconds when you start your wrangler, then the box has a problem. When the light on the knobs blinks, and you can control your HVAC system, it’s not an issue with the HVAC box. You need to have the rest of your HVAC system checked.  

How to replace the HVAC box on Jeep wrangler?

The HVAC Box on the jeep wrangler can be replaced by the removal of all dashboard control boxes and also any type of electrical commodities. Then you have to install the new HVAC control panel and module on the jeep wrangler. You can refer to the step-by-step process of removing and installing the HVAC control panel and module on the jeep wrangler below.

Removal of dashboard controls and electrical harnesses on jeep wrangler

  • Remove anything extra on the dashboard, such as phone mounts, radios, and adaptors.  
  • Remove the dust tray on top of the dash by prying it out to reveal a bolt underneath the tray, remove the bolt and set it aside.  
  • Remove the window switches that are located between the vents. To remove the vents, twist and turn them, then push them downwards. This will provide a space that a screwdriver can go through to the vent’s ring to a hole on the top part of the ring. Insert the screwdriver there, lift gently on the ring, then turn it. You can now pull the vent out.  
  • Reach into the opening where the vent was to the window control housing tab, then push the bottom of the tap. Once the base is out, you can start prying out the rest of the tab with your fingers or a plastic prying tool.  
  • At the back of the window control, there is a wiring harness. Use a flat head screwdriver to remove the red tabs by pushing one end with the screwdriver, then pull the other end with your nail. 
  • After removing the red clip, pull the harness of the window controls tab gently and wiggle it if it’s hard to remove, then set the window control tab aside.

Removal of dashboard panels on jeep wrangler

  • Remove the panel that is underneath the steering column. It’s held into place by clips. Start by pulling the front end of the panel downwards, then slide it out.  
  • Remove the screws on the bottom part of the steering column where it meets the dashboard, drop the steering column down, and lock it into position.  
  • Remove the panel that starts from the driver’s side covering to where the dust tray is. You can grab it from near the driver’s door and the ashtray, then yank it out but do not remove it altogether. It’s held into place by clips, and you don’t have to remove any screws.  
  • Remove the screw where you removed the window controls then you can now altogether remove the panel.

Removing and installing hvac control panel and module on jeep wrangler

  • On the control panel of the HVAC system, there are two tabs that you have to pull up and out gently. Do not pull it out entirely, as you will destroy the electrical harnesses at the back of the panel.  
  • Remove all the electrical harnesses that will allow you to remove the controls panel and enable you to access the panel’s backside.  
  • Remove the screws that hold the controls onto the panel. There are four screws on the cover, each screw being located at every corner.  
  • Once you have removed it, align the old module with the new module and ensure all electrical ports are in the same location and the exact number. Check the part number, and if the last letter is different, the control panel has had an upgrade or is from another supplier. For example, the old module has an A at the end, and the new one has a B at the end.  
  • Suppose they match in in part number and the number and arrangement of electrical ports. In that case, you can start reinstalling everything, ensuring you don’t confuse the old panel with the new panel.  
  • Ensure you reinstall every bolt and electrical harness you had removed, then test all the new control panel features.  

Conclusion 

The primary function of the A/C system is to keep the cabin of the wrangler cool or warm for its occupant, depending on the weather. If the weather is too hot or too cold, it causes discomfort to the occupants. Temperature discomfort when driving causes uneasiness to the driver, and it might lead to an accident.  

A faulty A/C control module keeps the A/C system in good working order. Any minor issue needs to be addressed before it turns to something significant such as causing damage to the air compressor, which is the most essential component of the A/C system.

replace HVAC Control box in jeep wrangler

If there is winter weather and you can’t use the A/C system, defrosting the car’s windshield is hard if you don’t have a window defroster on your windshield. Heating up the A/C defrosts the windshield, something you won’t be able to do with a faulty control module.

Suppose the cabin is not warm enough and you don’t have to defrost on the windshields. In that case, visibility is poor, and you might end up getting into an accident.  

The A/C system also plays a role in cooling the engine. If the A/C system cannot be controlled, the engine may overheat, especially during hot weather.