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Mopar Certified
Mopar Certified, Technician
Category: Chrysler
Satisfied Customers: 11329
Experience:  24 Year Factory Trained and Certified
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2000 Durango 4.7ltr check gauges light comes on and alternator

Customer Question

2000 Durango 4.7ltr check gauges light comes on and alternator gauge drops to zero. I replaced the battery and checked the 140amp generator fuse with an ohm meter (its fine). If I leave the engine off for a while the start it up the gauge comes back up and all seems well for a time then it drops again.
Submitted: 7 years ago.
Category: Chrysler
Expert:  Mopar Certified replied 7 years ago.

You pretty well have only a few options for this problem.

 

One is the alternator is bad and not charging the battery.

 

The wiring going to the alternator may be broken/chaffed or have high resistance.

 

If these 2 things are ok then your PCM is likely at fault. The voltage regulation portion of the charging system is controlled by the PCM.

Customer: replied 7 years ago.
What and where is the PCM?
Expert:  Mopar Certified replied 7 years ago.

Sorry, the PCM is the Powertrain Control Module......aka engine computer.

 

It's mounted under the hood on the right inner fender.

 

graphic

Customer: replied 7 years ago.
I should also mention that when the gauge looks good I measure a healthy 14 volts at the battery with the engine running. When the gauge drops to zero I measure between ten and eleven volts at the battery with the engine running. so I don't thin I'm getting a faulty gauge reading. What puzzles me is that it seems to be intermittent. I would think a bad alternator would just be bad all of the time.
Expert:  Mopar Certified replied 7 years ago.

Yes you are correct in your thinking about the alternator.

 

I suspect you have a wiring issue or a bad PCM.

Customer: replied 7 years ago.
how much would a PCM be likely to cost? Would it be worth while to try replacing the alternator first?
Expert:  Mopar Certified replied 7 years ago.

The PCM's vary a bit in price depending on the application. Probably 6-900 dollars.

 

You are asking me to guess at replacing an alternator and I cannot suggest that.

 

Dollar for dollar you might be wise to have a shop diagnose this for you........it would be cheaper than buying an alternator if that is not the problem.

Mopar Certified and 5 other Chrysler Specialists are ready to help you
Customer: replied 7 years ago.
Thanks. I guess I'll have to bring it in. I was hoping to avoid that. I appreciate your advise and prompt reply.
Customer: replied 7 years ago.
Just thought I'd let you know. I replaced the alternator and that solved the problem. Thanks for all of your help.
Expert:  Mopar Certified replied 7 years ago.
You're welcome.