I just replaced my alternator and voltage regulator, because the alternator went bad. Now even if I give it a little gas, the lights grow noticeably brighter, turn signal gets faster, and the hazards go at an almost strobe like speed. The alternator meter surges past the max as well. The voltage readings from the battery are ~12.8 at idle and 13.8-14 when I give it gas.

Also, to try and fix this, I charged the battery all night but nothing has changed as of this morning. The alternator is a 50amp.

One thing that is probably worth noting is that while hooking up the new alternator, the car would fire up and die with the two FLD wires in one position, I switched these and it solved that issue. I was under the impression that the two FLD posts and their wires could be interchanged so that seemed odd.

Should I be worried or did I just get a crappy alternator?

What is the make and model of your car?

The first place I would look is the battery connections, then engine grounding straps.

As far as the starting and dying with the field wires hooked up one way. Perhaps someone tapped into one of them and is using it as a feed for the ignition.

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85 d-100 HEI 2BBl
06 Toyota Corrola

All of that seems fine, its a '71 Plymouth duster. My money is on a bad alternator. Its hit or miss with the remans

Chryslers are notorious for having problems with there electrical systems.

The voltages you posted are not terrible and it is common for head lights to dim at lower rmps. A properly functioning charging system will produce 13.8 volts when the engine is off idle.

You have to remember the electricity is traveling through a lot of wiring(think voltage drop) and any corroded connector adds to the voltage drop.

Also if the headlight ground is bad the electric will find a way to ground even if it has to back feed through another circuit to get to it.

I had a bad rear chassis ground for the tail lights and I had all kinds of funky stuff happen when I would step on the brake. The gas gauge would drop to E, the front turn signals would light up, and if I had the head lights on the front were dim and the read tail lights would flicker very dimly, and the gas gauge would peg to E.

What led you to conclude the alternator was bad?

I personally have not had a problem with a reman alternator, however I have had problems with the new production voltage regulators.

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85 d-100 HEI 2BBl
06 Toyota Corrola

I would swap the voltage regulator with a known good unit to see if it is a bad voltage regulator. Just to be safe... Then clean the ground for the headlamps. Just as a curiousity how did the headlights and ignition behave with the old alternator? Did you ever try a field swap on the old alternator? If you did and the cargo started then, it's in the harness. I'd test it and repair oe replace the harness at that point.

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Leela: 1970 Dart 225 CID
Coulmn Shift TorqueFlite
7 1/4" Axle 2.76 Gears

Go ahead and save that weird car, the sedan, the 6 cylinder, the C-Body. If you want a big block musclecar and that's all you care about, your missing the point.

The battery wasn't getting a charge with the old alternator. Had AutoZone do a free test and then took it to AdvanceAuto for the same test just in case. Same results. Before the swap, I never had the glowing/faster turn signal issue. It just started after the switch. The car started fine with the old alternator, it just wasn't charging the battery at all. I will take the the regulator back for a replacement as soon as the roads are safe again and see if that helps. I just can't see it doing that because it appears to be doing its job just fine.

We'll see, I'll update with the results later. Thanks for all the help.

A process of elimination is in my opinion the best method to solve a problem such as this. However if you say it is with the alternator, it may be a faulty winding. I would get it checked out by a local eléctrica motor rebuild shop, if one exists near you.

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Leela: 1970 Dart 225 CID
Coulmn Shift TorqueFlite
7 1/4" Axle 2.76 Gears

Go ahead and save that weird car, the sedan, the 6 cylinder, the C-Body. If you want a big block musclecar and that's all you care about, your missing the point.

So I got a new VR today and had the same issues. Alternator is working fine but the battery is now getting >16v @idle D:

I'm guessing it's the wiring that's bad and I'm not consistently getting bad VRs. What gauge wire do I need to replace the current wires from the alternator to the VR?

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'71 Duster 225ci

It sounds like one of the brushes on the alternator is grounded. When the field wires were hooked one way it stalled; ignition + being shorted to ground. Hooked the other way & the alternator has max output; 16V or more. Time to swap the alt for another one. You could confirm by unplugging the green field wire, then see if it still (over)charges- it shouldn't charge at all.

If your car is mid 70's or older, you might want to consider upgrading the alternator output/B+ wiring to heavier gauge that goes direct to the battery or starter relay B+ post. 50A is alot for old bulkhead connections & ammeter.

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63 Valiant Wagon
225 - 4 bbl