Your Jeep XJ has a 90A alternator which is suitable for the default setup. However, it needs to be replaced when it goes bad or more accessories get installed.
So, I have decided to describe how to upgrade alternator on Jeep XJ. And, I have recommended aftermarket alternators with higher amperage.
In this article, you will also get to know how much it costs for a complete upgrade. Without further ado, let’s get started.
Can You Upgrade Alternator on Jeep XJ?
Yes, you can upgrade the alternator on your Jeep XJ without damaging any of the existing components.
The default or stock alternator in your car can meet all the electrical requirements.
However, things don’t stay the same as soon as you install more power-hungry accessories in your Jeep.
You have understood the need for upgrading this part. Now, I want to tell you that anyone can do the replacement by themselves.
Let me warn you about something. Changing only the alternator is half of the job. The other half requires upgrading the cable.
In the next part, I have explained the signs and symptoms of a bad alternator to let you know about the right of upgrading.
When Should You Upgrade Alternator on Jeep XJ?
As a partially functional alternator lets the engine run without much problem, you may not realize it until it’s too late.
Here, I have described the 7 symptoms you should look out for to detect a bad alternator.
1. Dead Battery
On one side, the battery keeps providing energy to run the accessories. And, on the other, the alternator fills the used capacity.
Whenever this cycle breaks due to a bad alternator, the battery keeps losing more energy than gaining.
Therefore, the battery soon dies, and you will see that the Jeep is not functioning anymore.
2. Dim or Overly Bright Lights
At some point, the alternator in your Jeep XJ may not be able to keep up with the demand.
Hence, the battery won’t be charged properly, and the headlight won’t get a consistent voltage and current.
In this case, you would notice that the light in front of your car is frequently dimming or getting brighter.
3. Accessories Not Working Right
When the battery is not fully charged, it can’t provide the amount of power required by the accessories.
Therefore, you will notice that they are not functioning properly. This symptom indicates a battery problem.
After testing the battery, if you see that it is working fine, you will have to suspect the alternator for the trouble.
4. Starting Problem or Stalling
The sole purpose of an alternator is to keep the battery charged. When it doesn’t operate properly, the battery gets drained more than it is charged.
Hence, it can’t provide enough power to the engine which results in frequent stalling.
And, being dead or completely out of charge makes the Jeep XJ not start at all. So, you can understand that these symptoms are significant.
5. Warning Light
Another obvious symptom of a bad alternator is seeing warning lights on the dash.
I know that it can blink for several reasons. And, an alternator about to go bad in a good or common cause among them.
6. Growling or Whining Noises
Hearing growling or whining noise is similar to the previous one. There are countless reasons for hearing concerning sounds.
And, having a bad alternator can be a valid reason. So, as soon as you hear something suspicious under the hood, you should get it checked by a mechanic.
7. A Crack or Physical Damage
I have listed this sign at the end because you won’t know until physically inspecting the alternator.
Either check it while doing regular maintenance of your Jeep or noticing do it after noticing any symptom mentioned above.
When there is a crack in the housing or any kind of physical damage, you will have no other option but to replace it.
How Much Does It Cost to Upgrade Alternator on Jeep XJ?
First of all, hiring a car mechanic to do the job, you possibly have to spend something between $80 and $130.
After that, the aftermarket part for upgrading can cost you around $130.
I need to inform you that upgrading the part will require installing a new electrical cable. It can cost you up to $120.
Also, there is some safety equipment totaling up to $50. Summing up, the cost to upgrade the alternator on Jeep XJ is around 300 dollars without the labor cost.
It is a bit expensive but you won’t regret it as the longevity of your car battery will increase dramatically.
My Top Recommendation on Jeep XJ Alternator Upgrade:
After doing some research, I have found 3 of the best quality replacement alternators in Amazon. Check them out.
A great replacement is a high output 160 Amp replacement alternator from LActrical. For Jeep XJs built between 1991 and 1998, you can buy them. Compared to the first product, this one is slightly costlier. If you liked this aftermarket part but have a 2000 model, you should check another model from LActrical that supports 1994-2004 4.0L Jeep XJs.
The best online alternator replacement deal you can find on Amazon is from DB Electrical. Their AND0023 is compatible with the 1991-1998 Cherokee XJ models. But beware, it is only 90 Amp. Because of its OEM specifications for Jeep, you won’t face any difficulties while installation. Also, you will love the customer service of the manufacturer.
The last product is from TYC. It has OE-compatible mounting holes in the right position so that you don’t have to drill additional holes. With rigorous and accelerated cycling tests, the manufacturer has ensured the quality of this replacement alternator. The model compatibility is not clear for this product. You should contact the seller to make sure that your vehicle fits TYC 2-13915.
How to Upgrade Alternator on Jeep XJ?
Though upgrading the alternator on your Jeep XJ is not a difficult task, you have to know how to do it properly.
- First of all, disconnect the plugs. Here, you have to go under the car and access the cables.
- While you are under the car, get a wrench to lose the bolts. After taking the mounting bracket off, the alternator will come out easily.
Tip: You have to take the whole mounting rig out to test whether the new replacement alternator fits or not.
- Now, place the newly bought alternator for your Jeep XJ on the bracket, and tighten the bolts.
Note: In case you notice that the new alternator is slightly bigger or mounting holes in a different position, you have to cut new holes. Also, one may have to trim some metal parts of the bracket to fit the aftermarket product.
- After installing the alternator in the car, you need to upgrade the wires and some connection terminals for smooth operation.
Reason for cable upgrade: For those who have bought a 160A upgrade alternator, the existing cable won’t support the high current.
- Cut the battery cables connecting the alternator at the same length as the old cable. Buy 2/0 AWG pure copper cable from Amazon as it can handle up to 190 Amps.
- Here, you have to attach a 5/16” Pure Copper Cable Lug Terminal Ring Connector on one side of the cable.
Pro Tip: At the battery end, installing a fuse between the cable and the battery can save your car from catastrophic electrical accidents. I suggest owners get a 250 Amp MEGA/AMG Fuse Holder Kit and a Littelfuse MEG175XP MEGA Slo-Blo Automotive Bolt-Down Fuse.
- Finally, connect the wires, and start the engine. I think that problem you have faced with the old alternator is now fixed.
I hope that you have understood the steps explained here. If not, you can watch this video to gain the confidence for replacing the part by yourself.
You now know how to upgrade alternator on Jeep XJ.
One thing you should keep in mind while choosing a replacement part. Getting a 120 Amp product is considered an upgrade.
Because the stock part has 90 Amp specification. The 2nd and 3rd products on my list have factory default specs.
Buying it can save some money but it will be a replacement; not an upgrade. I think you have understood my point. Now, buy one according to your needs.