Low voltage at idle

[rayjay]

I noticed tonight that sometimes at idle its appears my alternator is not putting out the juice. The volt meter is at 12. If I put it in neutral she goes back up to normal. Plus this is intermitent. When in motion no problem. Does the MM have a voltage regulator? I will be keeping my eye on this.

[MM2004]

I noticed tonight that sometimes at idle its appears my alternator is not putting out the juice. The volt meter is at 12. If I put it in neutral she goes back up to normal. Plus this is intermitent. When in motion no problem. Does the MM have a voltage regulator? I will be keeping my eye on this.

Sounds normal to me, as mine does the same thing. And am running UD's to boot.

Mike.

[Marauderjack]

I noticed tonight that sometimes at idle its appears my alternator is not putting out the juice. The volt meter is at 12. If I put it in neutral she goes back up to normal. Plus this is intermitent. When in motion no problem. Does the MM have a voltage regulator? I will be keeping my eye on this.

I found that the OEM volt meter in mine is only accurate at 14 volts!!:argue:

Use a good VOM to check it and you may see that 12 volts (OEM) is 13+ volts (VOM)!!!:shake:

I bought a new alternator because the OEM readings were low and erratic....BUT the new one is the same way according to the OEM gauge!!:mad2:

Marauderjack:burnout:

[2003godshead]

I began having a problem similar to this after I had to jump start my car. The voltmeter stays on 12 now, in park and shoots up to 16 V when I step on the gas. Also, it doenst like to run the A\C without dropping back down to 12 V. I have noticed no starting problems or dimming lights or anything like that, The gauge just to act seems different.

[Blackened300a]

Sounds normal for a stock gauge. I swapped mine out and with UDP's I put out around 13 volts at idle and when Im driving it goes up just above 14 volts.

[rayjay]

Thing is it does not always do this. Most of the time the volts stay at normal when I'm stopped at a light. :confused:

[MENINBLK]

Clean your battery terminals and clean the opposite ends of the cables
where the ground attaches to the body/engine
and the positive attaches to the power junction.
Also tighten the bolts to the generator
and make sure the plug is fully seated.

[Spectragod]

13.3-14.1 is normal operation. I would verify that your meter in the car is correct with a meter.

While the car is running, you can measure voltage @ the battery, it should be no less than 13.3 volts, keep you ground side of your meter attached and measure the voltage @ the alternator, there should be no more than a .5 volt difference.

SG

[rayjay]

13.3-14.1 is normal operation. I would verify that your meter in the car is correct with a meter.

While the car is running, you can measure voltage @ the battery, it should be no less than 13.3 volts, keep you ground side of your meter attached and measure the voltage @ the alternator, there should be no more than a .5 volt difference.

SG

The lights noticeably dimmed when it did this, so I know the meter was right about what was happening. Thanks MENINBLK, I'll look at that tomorrow when its supposed to be warm.

[kamikaze2899]

Just had a bunch of problems that began and ended with voltage issues.

Mine had a bad diode in it. At idle or low rpms, it wouldn't charge, then at 1k rpm or higher would be okay. Had to have tested at a local auto electric shop to have it diagnosed. It was also making a high pitched whining noise.

From what I've found, the MM is super sensitive to voltage issues. If you read my thread you'll see what I mean.

My advice would be to get it tested with an accurate meter/load tester.

Personally I'm saving up for the 200 amp alternator kit from Reinhart.