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Jeep Cherokee and Jeep Grand Cherokee 1984-2004: Why Doesn't My A/C Work?

Is your A/C not working the way it should? Learn how to diagnose the problem with the help of this article.

By Jerry Perez - September 15, 2015

This article applies to the Jeep Cherokee and Jeep Grand Cherokee (1984-2004).

Imagine reaching for the A/C switch in a hot summer day, only to be let down with weak and hot air coming out of your vents. Your Jeep's A/C system is intricate just like in any other vehicle. It's made up of multiple components that rely on each other in order to deliver the strong cold stream of air into your cabin that you desire. As the miles increase, the chances of one of the A/C components going out increase considerably. Follow this guide of common reasons why your A/C may not be working. Some of the reasons may be simple DIY solutions, while others may require professional repair. Keep in mind that the list begins with the easiest to perform, or least expensive to repair, to more complex and more expensive to repair.

Materials Needed

  • R134A recharge kit
  • Flat head and Phillips screwdrivers
  • Various size sockets and ratchet wrench

Step 1 – Check for leaks

There could be a leak in the system.

The refrigerant, air and gases that come into play for the A/C system to work properly have to travel through various hoses, gaskets and ducts. Sometimes, these may crack or become loose and leak. Follow these steps to check for leaks in your Jeep's A/C system.

  • Open the hood.
  • Locate the belt pulley driven A/C compressor.
  • Follow the high and low pressure lines and inspect for leaks.
  • Locate evaporator and inspect for leaks.
  • Run the engine for 15 to 30 minutes with the A/C on high, inspect underneath the vehicle and hoses for leaks.
Figure 1. Leaky hose.

Pro Tip

If you live in a location with extreme climate, it is important to check hoses and gaskets every couple of years for excess wear.

If there are no leaks, then move to this next step.

Step 2 – Recharge refrigerant

It could be out.

Your Jeep's A/C system needs something called R134A, which is a gas refrigerant that is stored in your A/C system and is cooled every time you switch on the A/C. Over time, the R134A will loose its effectiveness and need to be replaced. Follow the next steps to recharge it, it's fairly simple.

  • Purchase a R134A recharge kit at your local auto parts store.
  • Locate the high pressure recharge plug in your A/C lines. (Close to the firewall on the passenger's side.)
  • Plug in hose from the recharge kit into the connector and squeeze until empty.
  • Test your A/C.
Figure 2. High and low pressure connectors.

If the car has refrigerant, it's time to move on.

Step 3 – Check the evaporator coil

It could've failed.

Most people would think the A/C system cools warm air to make your cabin comfortable, but technically, the evaporator draws the heat out of air which is then cooled and blown back into the cabin. The evaporator can be housed inside the dashboard or in the engine bay depending on the year model, and looks very similar to the radiator. Due to its complexity, the evaporator is best diagnosed at the dealership or by a professional mechanic. But if you are sure your evaporator needs replaced, follow these steps to do so:

  • Remove the entire dashboard.
  • Locate the evaporator coil, which is located next to the blower motor.
  • Remove old evaporator and replace with a new one.
Figure 3. Jeep evaporator.

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