[rollin smoke in a'92]

So the power meter in my truck is reading low, I think, if you look at it , their are the four connected bars in the center, mines on the last connected bar, toward 8. Could it just be the battery?

 

[PPDMostWanted]

doubt it. when truck is running, unplug the battery and turn the lights on. It could be your gauge.

 

[Steve g]

doubt it. when truck is running, unplug the battery and turn the lights on. It could be your gauge.

Not wanting to contradict, but you should never disconnect the battery on a running vehicle that utilizes an alternater (old cars with generaters are not a problem). An alternater without a battery has the potential of producing run away voltage and damaging electronics including, but not limited to, the regulater and PCM.

Borrow a voltmeter, or buy one, (cheapies are $10 or less) and clip it on your battery cables. Compare the voltage to your dash voltmeter. Battery/charging system voltage at high idle should be around 14 volts, ideally 14.2. The hash mark to the right of centre on your dash board gauge should be around 14 volts. This is the regulated voltage of a fully charged battery. If your battery is low the running charge voltage should be a minimum of .5 volts higher than standing battery voltage and should rise to the 14.2 as the battery comes up to full charge. With all of your accessories on voltage should not drop below around 13 volts, but should never be less than .5 volts above what the standing voltage was (otherwise you're draining more than you're procducing).

If your voltage is in fact low it's not generally the bttery but rather the charging system.
Steve g

 

[Rattletrap]

My voltmeter in the gauge cluster does the same thing. Reads about 10 - 11 volts max ... never gets above that.

I checked it with a hand held voltmeter at the battery terminals and it was about 14 volts.

I asked a mechanic to check it out also and he told me the same thing, it is charging fine, voltmeter in the dash must be off in mine.

 

[malodin]

steveg is absolutely correct with now days technology and most alternators being interanally regulated or even electronically regulated by a voltage regulator, you place a HUGE load on the alt. to produce enough voltage to operate the vehicle, now this doesnt sound like it would be as much with a diesel but there is still a big draw on the electrical system and without a battery you stress it out. In my experience with my friends and selling autoparts and various other stuff, i have found that anything past 88 or so that someone "did the battery test" needed a new alternator within a month or so doing it.

 

[rollin smoke in a'92]

10-4 guys, problem fixed

 

[dodge91cummins]

i dont know about u guys but when i disconnect my battery cable my engine shuts off

 

[rollin smoke in a'92]

ok so I thought it was fixed but its not. its not charging at all, time for a new alternater? I cant even roll my windows down with out the radio shutting off, I have to jump it everytime I shut it off.

 

[nkendall07]

WOW WOW WOW dont buy an alternator yet the alternator is controlled by your computer because of this I have put in the parts to make mine an internal alternator the way to check it is run a hot wire and a ground over to the alternator. There are two terminlas next to each other on the alternator. They are the small ones; run the hot to one and and ground the other side becareful because this will cause the alternator to go full out and put out as much as it can check the battery voltage then if the alternator is good it will be around 18-20 volts dont let this go for long because it can blow a battery up!!!!!!!!

 

[Paccool]

Check the air conditioning and cruise control. These usually quit as well if it is the PCM.

 

[nkendall07]

My a/c quit also at the time this happened but my cruise still works?? But now have all that fixed!! Didn't realise this was the same thing so learned something there thank you pacool

 

[rollin smoke in a'92]

I fixed it, it was the alternator, $165 and change and a couple of hours and I was up and runnin, of course I had to change the pully, but no big deal