[kmett]

over the winter i noticed the truck was gettin hard to turn over in the winter but i thought i would be able to hold out gettin batteries. well i finally had to get some this weekend. however, with finally monitoring my volt meter i notice that while driving it will stay right around 14volts but at idle will get offly close to the major line before it has the gap and then 8volts.

does this mean that my alternator is havin a hard time keepin up when it doesn't have the motor spinnin it good? should i take it off and have it tested at advanced auto or somp like that? don't want to get stranded or shorten the life of these batteries.

Thanks

 

[CMMINS]

Before you pulled the alternator, just check the batteries with a fluke meter at idle. that way you know exactly what the batteries are getting charged at.:thumbsup

 

[Mopar1973Man]

At a idle its must be between 13.5 to 14.5 Volts... Anything above or below that the alternator / regulator is failing...

I would pull the alternator and have it checked. If that checks out the PCM is at fault (voltage regulator)...:w:

 

[ponytamr2]

Check your battery as well, if your battery is bad it will cause voltage issues and will eventually ruin your alternator.

 

[Esjayco]

I had a similar problem with my 99 a year or so ago. The PCM wasn't exciting the alternator. I couldn't wait two weeks to send off my PCM to get rebuilt. We put a hotwire from the key to excite the alternator. All has been fine, but still thinking about getting a rebuilt PCM