Jeep Wrangler Heater Not Working – Common Reasons Why

Most Canadians know that our winters are terrible. They can be terribly cold, the snow often builds up till it’s at least a few feet deep, and our cars refuse to start. But what’s worse is when your heat doesn’t work. All that work to get it started, cleaned off and running, only to find out you’re in for a very cold drive to work. In this case, we’ll be talking all about the Jeep Wrangler heater not working. And to be more specific, the reasons why this happens, and how to fix each of them. But before we do so, let’s talk about how a vehicle’s heater actually works. Are you familiar with a coolant system? Well, in simple terms, the air is pumped in through your radiator using what’s called radiator fans. The fluid running through your radiator is cooled by this air, which is then sent throughout your engine block. In most modern cars, there are a few more steps related to heat. The air that runs through your radiator is going to get hot once it’s done with. To make things efficient, car designers have decided to send this air through your heater core. This core is what actually warms the cabin of your vehicle (or in this case your Jeep Wrangler). And yes, the air is of course filtered. You wouldn’t want to be breathing in the fumes from your engine bay for all that long!

Before we jump right into the biggest problems facing Jeep Wrangler heaters, we’d like to point out that there are hundreds of different reasons as to why your heater won’t work. These are simply the most common. If the following options won’t solve your problem, we recommend you take your Jeep to a licensed vehicle technician. They’ll be able to diagnose the problem and figure out exactly what’s going on.

Common Reason Number One – Blower Motor and Resistor

This particular part is responsible for taking the heated air from your coolant system and pushing it through your hot heater core. From here the air will pass through your ventilation system and enter the cabin. In a Jeep Wrangler, this part is typically located behind your glove box. Before taking everything apart to see if it’s broken, we recommend turning your heater on listening for a rattling sound. It may also sound like rubbing or gears grinding. Typically blower motors display signs of bearing issues and even fan blade issues in some cases. If you don’t hear any noises, we recommend you check the resistor (which is a part of the blower motor). Once again, no need to take anything off. All you need to do is run your heater at different levels. If it works on some levels and not others, chances are your resistor needs to be replaced. Unfortunately, there is no simple repair for this issue. All you can do is replace the broken parts, so take it to a trusted mechanic.

Common Reason Number Two – Incorrect Coolant Level

Unlike the previous option, this problem is quite easy to fix. All you need to do is check your coolant level. It may also be labeled antifreeze. Interestingly enough, just because your engine is getting hotter, doesn’t mean your cabin will as well. If anything the interior of your vehicle will get colder. If there isn’t enough coolant, your entire coolant system won’t work properly. And remember, your heater core requires your coolant system to work properly for it to do its job.

All you need to do to fix this is to add more coolant. Fill it up to the appropriate level, and you’re good to go. Take your heating system for a test drive. If the problem persists, you need to check through some of our other options. If the problem no longer persists, you’re good to go. Just keep an eye on your coolant level from now on. It’s not good for an engine to run with no coolant.

One thing to keep in mind when refilling coolant is the year of your Jeep. Certain new models can only use approved Jeep coolant. Using anything off-brand may damage your engine, and will certainly not make your heater core run any better. If you’re not sure whether or not your Jeep needs approved coolant, check your owners manual for more information. A lot of Jeeps nowadays use HOAT coolant, or in other words, Hybrid Organic Acid Technology coolant. This particular type of coolant is designed to work with Jeep engines. Engines in most new Jeeps aren’t designed to work alongside regular or off-brand coolant, so do be careful!

Common Reason Number Three – Thermostat

Our third common reason for a heater not working is a broken thermostat. Your heater core, and sometimes even your radiator, is designed to work in accordance with a thermostat. If this thermostat is damaged or needs calibration, you may damage your car or simply lack proper heating. Sometimes thermostats simply need recalibration, whereas in other cases they can be quite expensive to replace.

Common Reason Number Four – Hoses

As we mentioned earlier, if your coolant system is not working correctly, your heater core won’t either. So, if you have a damaged component in your coolant system, like a hose, odds are nothing’s going to work right. Not only will you have no heat in your vehicle, but your engine will be overheating, coolant will be leaking all over the ground, and everything will just be falling apart. In order to solve this issue, you can either replace the tubing all together or just patch it up using a Jeep patch kit. You may also want to top up your coolant (see common reason number two) to avoid issues.

For More Information

For more information we recommend you visit your owner’s manual. It will tell you exactly what type of coolant your vehicle needs, the type of heater core you have, and so much more. Feel free to reach out to us at any time, for we are one of the best sources of Jeep knowledge on the entire world wide web.