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As far as I can remember my voltage gauge has always stuck straight up, right in the middle and has never moved during normal driving. Driving to work today I noticed that it was reading a bit higher than normal. Nothing serious but it was a few degrees to the right. On the way home it was a bit high as well but less so. After a stop to get some take out it was reading straight up again. After a gas stop it was a bit hight but then got a little low (to the left of center) when I was at a stop light. Once moving again it moved to the right some more and was acting almost like the oil pressure gauge.

So is this normal or is something going out on my truck (have about 49K miles and everything is stock under the hood other than a AEM intake)

Thanks,
Jason
 

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I dont know about moving with the rpm, maybe bad alternator, but i would first check your battery cables for corrosion or loose connections as well as at the alt itself. Corrosion and lack of contact can cause funny things to happen.
 

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Can you get the Alt checked with it still being on the truck??? I thought you could but some one told me i couldnt... My volt meter is always straght up or a little below and trying to die!!!



Willis
 

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My truck has always varied like yours. At least for the last six months or so it reads about an 1/8th inch to the right of center. It drops when I hit a light and kick on one of my turn signals. My lights also dim a bit at night when I raise or lower a window. The dealership told me that the alt was fine. I also have a yellow top Optima for my subs, and even when the amp is off, it still reads a bit high.
 

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dale3fan3 said:
my lights dim too when I use the windows at nite
Yeah it is quite annoying really. My 2-12" subs and 700 watt amp doesn't dim my lights, and I don't have a Cap, high end alt, or larger wires...but I roll up a window, people think that I am brighting them. :crazy:
 

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deathscripture said:
Yeah it is quite annoying really. My 2-12" subs and 700 watt amp doesn't dim my lights, and I don't have a Cap, high end alt, or larger wires...but I roll up a window, people think that I am brighting them. :crazy:
Damn mine is barely noticable. If yours is that bad I think something is wrong. I also am running 2 amps and no cap and I have no lights dimming from it. I guess the window motors draw a lot of amps
 

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Well, I guess that it was sarcasm more than anything else, it isn't really too bad.
 

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Have the alternator checked, do a load test on the battery and spend a few minutes checking all the cable connections on the charging system. If the alt and battery test ok, it is more than likely a bad ground connection somewhere.
 

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Sounds like a normal electrical system to me. Mine varies like that all the time. different time of day, different loads, different readings.
 

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Jay5.9L said:
As far as I can remember my voltage gauge has always stuck straight up, right in the middle and has never moved during normal driving. Driving to work today I noticed that it was reading a bit higher than normal. Nothing serious but it was a few degrees to the right. On the way home it was a bit high as well but less so. After a stop to get some take out it was reading straight up again. After a gas stop it was a bit hight but then got a little low (to the left of center) when I was at a stop light. Once moving again it moved to the right some more and was acting almost like the oil pressure gauge.

So is this normal or is something going out on my truck (have about 49K miles and everything is stock under the hood other than a AEM intake)

Thanks,
Jason
If you go to an Autozone. They can check the battery and alternator while it's still in the vehicle and they do it for free. The hard part is finding one that has a person who knows how to use the damn tester properly. I went to two different ones and neither knew the correct way to hook the thing up. Oh they talk all confident and crap and say that they know what they are doing and perform the test. The tester can give a very comprehensive test. It "should" show you the starter draw, battery CCA capability, alternator voltage output, and alternator max amps output. Also should be able to show you what the load is, on the alternator, with all or certain accessories on. Most of these kids that work there, weren't around when the VAT-40 was the industry standard tester. That thing could tell you as much, if not more, as these newer automated testers can. You just had to do everything manually. Now they're kind of like a plug and play type thing.

Now as far as your voltmeter goes. I'll pass on what happened with my truck and the dealer. It sounds like yours is doing what mine did. On a colder day the voltmeter (DCVM) would read higher than usual. On a warmer day the DCVM would read lower. Lower to the point of noticing dimmer headlamps and slower power windows and slower blower motor speed. Very annoying if you ask me. I thought "Maybe it's just me" so I put a Fluke digital voltmeter on the battery and checked it out. Sure enough, the voltage was dropping down to 12.5vdc at idle (550-600 rpm) with the headlamps on and the blower on high. If you raised the rpm up to even 800 the voltage would climb up to 14 to 14.2vdc. This all started to happen at about 34K miles. Like you, the DCVM always pointed straight up or an RCH to the right. I still was under factory warranty so I took it in to Dodge. I'm going to try and shorten this up. They saw the same readings and said to me that it was normal. I argued that it never did it before and wanted a new alternator. After several days of some back and forth arguing, they replaced it. This all happened in the Fall and we didn't have any warm weather until Spring. So at the time it seemed like the problem was gone. When the warm weather came back so did the "problem". I have since replaced the factory battery with a yellow Optima and even replaced the belt. Nothing changed. During the course of this saga I did some reading about this charging system. First off, there is no voltage regulator. There is a voltage regulation function in the PCM. (That very expensive computer thing for the truck) It takes inputs such as RPM, battery voltage, battery TEMPERATURE. It (PCM) takes all of this input and calculates a target voltage that is best suited to handle current load and to charge the battery without overheating the battery. According to the service manual there is no way to calculate manually what the PCM should be calculating for a target voltage. My only guess, short of replacing the PCM, would be to try replacing the battery temp sensor.
 

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Sounds like you can just do an overdrive pulley on the alt then.
 
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