Car wont stay running (93 jeep grand cherokee laredo)

jeep
grand-cherokee

#1

Hello everyone.

I am having an issue with my vehicle. It shuts down at random, 1 thing after another until everything just shuts down. I have replaced the battery, the alternator and the 2 alternator fuses. The battery guage in the vehicle still reads 9 and the alternator wont kick in and take over when the battery dies.

Any help would be great.

Thanks.


#2

I suggest you check the charging voltage while the engine is running to see if the alternator is working. First off, make sure the battery warning light turns on when you turn the ignition switch to ON or RUN. If that is okay then start the engine and check the voltage between the alternator output lead and the positive battery lead. If things are good you should see less than .3 volts there. Then check the voltage from the alternator output lead and chassis ground. You should see around 13 volts. If that is good then measure the voltage on one of the fuses in the panel under the hood and ground. You should have about 13 volts there also. If you don’t have a meter to make tests with then you should get it to someone who can do the tests.


#3

The regulated voltage from the alternator is controlled by the ECU/PCM.

So the computer may be preventing the alternator from charging the battery.

Tester