My wife called me this morning and said our recently bought 2000 jeep cherokee was running 19 volts on the gauge while driving..... she said when she came to a stop the volts would go back to normal... she stated has she started driving again the volts would go back to 19.... im new to jeeps but not turning wrenches.... i was wondering if you guy could lead me in the right direction??? i did alittle research and found something about the voltage regulator in the pcm.... new pcm is stupid expensive and wanted to get some advice before spending 800 plus dollars... can yall help me out???? thanks

 

What engine do you have....4 cylinder or 6 cylinder?
Can you read the name on the Alternator? Post a picture?

First thing you need to do is check the actual voltage at the battery with a volt meter.

Auto Zone or Advance Auto will check your alternator for free if you can't manage it.

 

Where are you located? What was/is the outside air temp when you see this problem?

 

its a 6cylinder 4.0 i dont have the jeep at the house at the moment.. the wife is still at work... and i live in virginia beach va and the temperature today is around 62-64 and rainy

 

i dont know if it will make a difference, but the battery in the cherokee is a used battery... it had major front suspension needs when we bought it and i havent gotten a chance to replace it yet.....

 

Good batteries are good for about 5 years, el-cheapo's are good for about 3 years.


If/when you pull your battery, check the condition of the battery temp sensor in the battery tray and uncouple the battery temp sensor connector and inspect for corrosion.


There are tests you can do to the temp sensor.


Battery temp sensors have caused charging problems.

 

i believe i found the issue.... checked the voltage going to the battery and it was 14.25... checked the ohms on the battery temp sensor and that checked out.. i noticed some corrosion on the ground battery terminal and decided to clean the terminals and seemed to fix the issue... didnt realize corrosion could cause that much of an issue