New Regulator ?s

['71 Dart Custom]

I have some questions about voltage and regulators. I had to buy a new voltage regulator today. The old one started cutting out most of the time, but would work enough I was able to keep driving the car. Before it started going out I noticed that my volt gauge would read 15 volts for a while after I first cranked the car but would drop down to just below 14 (13.8's perfect, right?). Now that I replaced the regulator, I crank the car and the factory alt gauge surges up to the 3/4 mark then slowly drops to just above the 1/2 mark (never did that before) and my volt gauge is reading a steady constant 15 volts. I've read other posts on the forum of people smelling wires burning at 16 volts.
My question is, does it sound like the regulator is faulty and what are the tolerances as far as voltage is concerned. What's too much? At what point do I shut the car down to avoid frying wires?

I HATE wiring problems:banghead:

 

[skykeith]

Sounds like a bad regulator, since the one that died had been properly regulating the voltage. Make sure the regulator has a good ground.

 

[67Dart273]

There can be "simple" problems cause too high voltage, known as "voltage drop" either in the hot side of the wiring harness or the ground path TO THE regulator

So, do the following, do these checks first with everything off except the engine, and again with the heater, lights on

Start the car, get the RPM up (fast idle) to simulate "medium cruise" and get the battery "up."

Now put one probe of your meter DIRECTLY onto the battery negative post, the other probe DIRECTLY onto the regulator case.

You should see VERY LOW voltage, the lower the better. Zero is perfect, over about .2 (two tenths of a volt) is too much, and indicates a poor ground path.

Now check the same thing on the "hot" side. Put one probe directly onto the battery POSITIVE post, the other probe on the regulator IGN terminal (blue, I think.) Once again, Zero is perfect, and over .2V or so is too much.

 

['71 Dart Custom]

Went back to local NAPA today. He agreed that regulator is bad (his meter showed 15.3) said he'd have me another one in the morning.

 

[pauls340]

I have a NOS regulator which I bought for a Rallye Dash and it is for a nonrallye dash #3592899, $24+mail