Let me start this off by stating that the car has new AC delco cables, new AC delco alternator, and new red top optima battery.

Car starts with good voltage, over 13v, then after running for a bit without running any additional accessories will dip down just above the yellow area.

Been fighting this problem for years but really want to start enjoying the car again and run AC, headlights, and blinkers without fear. Just wondering if anyone had advice on where/what to check next.

Thanks

 

Maybe a broken wire somewhere? I know when I put my car back together after my heads and cam I missed plugging in the small wire on the lower side of the alt and the car would not charge. Not sure where that wire goes, but it is pretty light gauge. Any chance you may have gotten mice in your garage?

 

What's the reading from the alternator? Should be a steady 14.5 volts.

 

Can you verify with a volt meter that what you see on the gauge is correct?

 

I'll check readings at alt and battery tomorrow anywhere else I should probe while I'm at it?

 

Your alternator.

 

Probed at the alternator hot wire and battery today while running and warm with AC on. Gauge read right at the start of the caution area (approx 11 or so volts) and handheld volt meter read 14.2v.

Should I ignore what the gauge is reading then? Is there a way to correct this?

 

Next, I would check the voltage while the gauge is reading correct and see what the actual battery voltage is during that time.

If it's the same 14.2 you had warm...that sounds like a gauge or wire issue.

If its like 16+ volts you have a alternator issue.

 

Alright will do, thanks