The Jeep YJ’s tachometer serves an important purpose, providing the RMP value of an engine that essentially reveals the vehicle’s true health. Knowing the value would help you determine how well the engine is performing.
So, any problem with this gauge is surely not good for you. There can be many reasons. The most common reasons that the Jeep YJ Tachometer is not working include a faulty needle, blown wire or damage to the inside parts of the tachometer, a faulty fuse, and the LED of the Jeep YJ not working properly.
In the rest of the article, we will try to find out why the tachometer issue in the Jeep YJ appears, what the common reasons are, and what you can do. Keep reading to find out more!
Why Does the Jeep YJ Tachometer Not Work?
Before we describe the reasons, here is an example of symptoms you may face with a tachometer. The most obvious symptom is: the tachometer is not working: the needle has stopped at zero or is stuck at any other number. Although other gauges are fine, the result is the same: faulty tachometer.
Reasons for why the tachometer does not work are not difficult to find out. There are two basic reasons for the erratic readings of the Jeep YJ tachometer. It may be due to faulty wiring or a faulty tachometer. The most common reasons are given below.
- Faulty needle, including broken needle
- Blown wire or poor wiring connection
- Fuse has melted or blown
- Faulty LED
4 Easy Fix For YJ Tachometer Not Working Issue
Now we have come to the main issue of our discussion. This section will comprehensively analyze each reason for the faulty Jeep YJ tachometer.
1. Faulty Needle: Rotate the needle Counter Clockwise
The needle may occasionally rotate to the bottom of the gauge. As a result, when the engine is running, the tachometer may function but stop at the stop sign, preventing the needle from crossing the zero line.
To put it in simple words, the needle was not on the correct side of the tiny step at zero. You can break the pen and turn the needle to the top side of the stop in a counterclockwise direction to fix the problem.
Suppose there is an issue with the needle or the tachometer in general. The best likely solution is to replace the original tachometer. The average cost of the Jeep YJ tachometer is somewhere between $50 and $200. Here is a list of a few names.
They are available in many online stores. For 87-91 Jeep Wrangler YJ with 2.5L OMIX 17215.10 Tachometer or 6 Cylinder Tachometer RPM Gauge Dash OEM.
2. Blown Wire: Remove the Wire and replace it
Sometimes the inside component of the tachometer gets damaged. Inside, faulty components include damaged or blown wires. Tachometer failure or a display issue are two possible outcomes of the wire damage.
If you think about it logically, then there must be a wire or something that sends the electrical signal to the tachometer. Maybe there is a wiring sensor and wire from the ECM or PCM to the tachometer that sends the necessary voltage. Test everything and ensure there is a steady voltage.
There can be two situations for a blown wire: the voltage was higher than necessary or the low voltage. When the tachometer has a display problem, that indicates a lack of voltage in the wire. Additionally, check the ground at the tech connector in the dash.
If you have to replace or repair anything inside the tachometer, you may need help from an expert. We are not sure what the cost of repairing the damage will be, but we think the mechanic will charge around $150 per hour.
3.Faulty Fuse: Replace Fuse
It is highly unlikely that the Jeep YJ has a separate fuse for this small gauge. However, it is worth inspecting this area. The Jeep YJ fuse box is located under the dash.
The location is in the engine compartment. Anyway, you will have a detailed diagram and picture in the manual or check online for details.
The fuse saves the electrical component, preventing the failure of the electrical system. Checking the appropriate fuse is extremely important when an electrical device is not functioning. Check all the fuses at a time. Here are a few things to remember.
- Before changing the fuse, other devices should be turned off
- replace the fuse with the new fuse
- Make sure the replacement fuse has the same amperage
- Make sure to contact the expert.
4. Faulty LED: Replace the Faulty LED
The reading may not be shown if the LED screen is broken or faulty. So, if you notice any issues with the LED, you must replace it. With the new LED, you can monitor the vehicle’s performance.
How Do You Test the Jeep YJ Tachometer?
Since these could be issues with the wire, the best way to determine the issue with the wire is to test it. You need a voltmeter to test the wire. If the wire is good, then something else is responsible for the issue.
Basically, you can test the Techonometer in two ways, using a handheld tachometer or using a multimeter. Both can be purchased from the automated store or online, depending on which one you want to try.
If the voltage flow is expected as it should be, the wire is fine. If, on the other hand, a voltage reading is not expected, it may be that the tachometer is busted, or you should find some other reason for the issue.
Using a Handheld Tachometer
Before you try either of these two, check the vehicle manual for the directions. The manual has a detailed discussion, including wiring diagrams, ports, and everything you want to know. You can try it yourself, but if you are not confident, get help from an expert.
After you make sure where to attach the handheld tachometer to the engine, we do not know whether you can use a handheld tachometer on the Jeep YJ, but this could be an option worth knowing.
Anyway, if you can use a handheld tachometer, then the engine tachometer reading should be within 10% of the reading of the handheld tachometer.
Using a Multimeter
Another way to test the wire is to use a multimeter. Doing the same, you must find the detailed description from the manual and then check the voltage reading.
If the reading is OK, then the issue is somewhere else. Most likely, you need an expert so he can find out.
You will get to know the reference voltage by reading from the manual. The Jeep YJ most probably has 12 volts in the wiring when the key is in the on position.
Also, the wire that comes from the ignition is around 10. I don’t know if you have to check the wire from the ECM.
Again, the detailed description must be followed from the manual. If you are not confident, let an expert handle it.
A mechanic will try to find other reasons for the issue if there is no issue with the wire.
By now, you have a pretty good idea about the Jeep YJ tachometer issues. Here, we have compiled a few more important questions that people ask. By going through them, you can clear up more of this issue.
How Do I Know Whether the Jeep YJ Tachometer is Bad?
By looking at the tachometer, you will know if it is functioning properly. When the car is moving but the meter needle is stuck on any number, that means a nonfunctioning tachometer.
Also, sometimes the needle moves a bit erratically. When the engine is running, the tachometer should move accordingly to give you the right measurement if this is not the case. The tachometer is faulty.
How to Read the Jeep YJ’s Tachometer Reading?
The Jeep YJ tachometer gauge has many numbers, such as 30, 40, or 70. When the Jeep runs, the needle should point to any of these numbers or run between two.
For example, it points to 70. To get the actual RPM, you need to multiply this by 100, which is 7000. It is the actual RPM.
How Do I Know My Tachometer Reading is Normal?
If your tachometer is not behaving erratically or fluctuating less, the tech reading is probably fine. When you start the engine, it should jump slightly but return to normal as you adjust the speed.
The ideal tech reading should be when the engine is idle, 10 to 20, or 1000 to 2000 when multiplied by 100. When you accelerate, the tech jumps a bit; then it settles down between 2000-3000.
What are the Different Types of Tachometers?
There are a few types of tachometers. Most analog tachometers consist of a needle and dial, whereas most vehicles are equipped with digital tachometers, which consist of a led or LCD and other features.
The other two types of tachometers are contact/non contact tachometers and time and frequency measuring tachometers.
There you have it all. The tachometer is not very complicated and has nothing to do with how the Jeep YJ runs. It does, however, serve the important purpose of delivering messages about the health of your vehicle.
When the tachometer does not work, the best way to approach the issue is to get to the root cause of it. Let the expert handle the issue if you do not have any previous experience or lack confidence.
We believe the information we have shared in this article was helpful. It at least increases your knowledge of tachometer issues. You can, however, broaden your search and learn more about it.