Voltage gauge all over the place

[diemer]

Past few days I've been having voltage issues. First noticed it with air blowing harder and softer at times. At night the headlights keep flickering/dimming and the voltage gauge drops down below the halfway mark

I'm guessing our voltage regulators are internal? Fortunately the alternator looks very simple to replace. Considering a used one for $50 as I've always had good luck with used alternators - rather than a $160 replacement. Have almost 200k on the stock unit.

 

[diemer]

Just had my battery and alternator tested. Both tested good. So strange. It doesn't seem to do it until the car warms up. Any other ideas on what I could or should check?

 

[YukonXL04]

does the voltage drop only at idle? or does it drop while driving as well?

 

[diemer]

I actually haven't noticed it at all during idle... only while driving.

 

[johninsc]

I have the same issue. I crank it up in the morning or anytime really and the whole electrical system is fluttering, flickering, or pulsating. It's more noticeable when dark. Then when I'm riding along and let off the gas it gets dim but comes right back. Someone told me it's the diodes??

 

[PlazaEJ]

Guys, have you checked your battery cables for looseness and/or corrosion, at the battery and the ground end of the negative cable? Or, perhaps, the cable connections at the alternator?

 

[ccapehartusarmyINF.(ret)]

mine started reading all over the place and i found it was my positive battery terminal was just a teeny bit lose and i figure naw this aint gonna fix the problem but sure enough everything was back to normal

 

[diemer]

Got around to replacing the grounds and pos(+) to the alternator with 4ga wire. Still didn't correct it. It's not as bad during the day but when the headlights are on it will continuously dip down to around 10 and spike back up off and on. Also seems to happen more when the blower is going.

Any other ideas of what it could be? I'm at the point of just going to pick a part and grabbing an alternator to see if maybe it's the internal voltage regulator. Keep in mind I've put about 1500 miles on the car with it doing this.

 

[F'in-hoe]

This happens to me as well. I had the battery tested and they said it had a dead cell and most likely the problem. Gauge does not drop or spike at all.