It seems the only way to wake up my alternator is to rev the motor up to about 3K, and than let off the gas. From there it will idle at 14+ volts. If I just start it, it will hang at the battery voltage (around 12.5 or so).
Whats funny - if I have it running at 14+V, and I shut it off than restart it right away - I have to rev it back up to 3K. It's like it resets after being shut off.

I just replace it with a reman. Both units had the same symptoms.
The unit on there now, is a Eighty something amps Autolight.

Does this sound like my alternator pulley is to small??? symptom whise...I have a set of March pulley, but there the high water flow ratio version. I just pulled the data, & the pulley is 2 3/4”...

A attached a drawing of my charging. It's about as simple as it gets. The car basicly has wiring to be a racecar, so it's all new wire, & all soldered. I average 12-14 gauge on most things, and the charging is 10gauge.


Thanks for any input...

Ron

 

Is it a one-wire alternator? If so I think they have to be spun up some before they will begin charging, then they will charge at idle, but I don't think it is 3000 RPM, maybe 1500 would be normal.

 

I just pulled this off a web page:
Self-Exciting Alternator:
Is an alternator that uses a special voltage regulator that doesn't need an ignition wire to activate it.
This type alternator only requires a battery wire hooked to it. The voltage regulator contains
circuitry that uses the residual magnetism in the alternators fields to determine when
to turn the alternator on. The regulator does this by sensing the RPM the alternator is turning,
when it gets to a certain rpm the voltage regulator "turns on". Typically you start
the vehicle, rev the motor slightly then alternator starts charging. This type alternator is
commonly used on custom cars & trucks, tractors and other non standard applications when
wiring is a factor. In choosing this type alternator you must consider, do you want
to rev your motor slightly to get the alternator to turn on. Also when using the self-exciting
alternator on tractors or other slow turning motors does the engine
have enough RPM's to start the alternator charging. This can be overcome by using a smaller
pulley or by adding an ignition wire.


One-wire Alternator:
Is another name for the Self-Exciting Alternator mentioned above. You only need connect the battery wire (one-wire).


Two-wire Alternator:
Most standard and all self-exciting regulator alternators will work using the two wire setup. Two wire means that you use the battery wire and an ignition wire to activate the alternator. With this setup the alternator starts charging as soon as the engine is running


Three-wire Alternator:
This setup uses a battery wire, ignition/warning light wire and voltage sensing wire, Three wires.

 

Does your "Choke" light come on when you turn the key on with the engine not running?

 

What choke light??? and the only key is my quick release wheel...

:sillylol:

Yea, it's basically a (3) wire stock alternator with only the Bat & ignition wires hooked up.
Now here's the question, do you suppose I have the ign wire on the wrong terminal (i.e. the gauge terminal)?
Since the regulator isn't a self energizing setup(i.e. one wire internal setup), this might be why I need to get it up to 3K to get it to turn on...

Here's the setup, I have the ign wire hooked to the bottom terminal & the ign wire is connected to the bat wire about a foot down the harness.


BTW "StangKiller" that was some awsome info - Thank you -
Yea, blipping the throttle isn't a big deal, but having to fire it up to 3K w/Holley MaxFlow is a little to exciting with a cold motor and a chokeless carb

Ron

 

R/T,

StangSmasher is right - you're a prime candidate for a one-wire alternator (I call them "Floozy" alternators - they put out as soon as you excite them just a little).

I also see another issue. Your intake has a Holley bolted to it... j/k.

If you want to retain the stock alternator, visit your local electronics supplier and get a 10 ohm wirewound resistor, 5W minimum. Wire it in an ignition-switched circuit to the 'B' terminal of the smaller alternator connector. This will provide the differential voltage for excitation of the regulator. Then she should put out...

Before hard wiring everthing, mock it up with a jumper/test leads while the engine is running at idle and see if the alternator responds. I'm fairly certain on the resistance, but I'm sure it was between 10-50 ohms.

 

Thanks, Vader...

I'm going to give that resistor a try. Now how did that go ? ROY G BIV?

Ron

 

BBROYGBVGW actually. But they dont use that for resistors over 1/2 or sometimes 1 watt. A 5 watt resistor will just say 10(omega) on it.

 

holy crap thats a 3rd gen in the pics? got a web site?

 

I see what your saying 'slickrock55'...
I found this on radioshack.com... (Pic below)

I'll hit them up tomarrow, for a 10 & 50 ohm 10 watt. (I only saw 10watt.) I'll play with that, and tell you guys the results.

'My86Firebird' I have a website (www.ronterry.com) but right now it's a big 'o' blank page...

Ron

 

LOL you can say that again

 

OK, here we go...

I use a 10ohm resistor between the ign or the #2 terminal.
That didn't help, so I was wondering what's the real difference between my system and a stock system. The dummy light or the (RB ) choke light.
So I just threw in a 12v light from the battery to the #1 terminal or field connector.
I started it up - the light started flickering & then off & it started charging at 1K.

So what’s the deal with this? It definitely caught me off by surprise! Should just wire a warning light to the dash?

Ron

 

The warning light is an excellent idea. Then if the alt ever dies, you'll know it. Hook it up with one terminal to the ignition circuit (not battery), and the other to the alt terminal in question.

The alternator needs some way to "know" that the key is ON. Without the light, it can't tell, and stays asleep. The light conducts current into the field circuit, without which, the alt will never "start". It doesn't take alot of current, but it definitely won't work with none at all.

Don't just run a wire with no resistor or light bulb; it will work, but under some circumstances, it can burn out the diode trio, by trying to run the whole car's electrical system through that wire via the diode trio, rather than through the main rectifier bridge.

I sort of knew you'd work your way down to this point sooner or later.

 

Ha Ha, yeap your right...

I guess I'll run it to my little FIDADADID fusebox I have on this car.
Don't worry the fusebox is switched. I assume it doesn't matter as long as it's switched, right?

I'll have to hit up Radio Shack again get another cool little red light...


Ron

 

Hey Ron,
Do you have to remove the steering wheel to see your tach?

Ill sell ya my ses light...cheap.

 

Hey Riley,

Naaa, the tach is actually very viewable. The fuel gauge is a different matter
I only use the tach for speed estimate (not a drag car, but more a road racer). There's a slip of paper I tape to the dash when I'm out here testing, that gives me rpm to speed.
Also if you pull the cover off the LED - you know when you hit peak HP. Beyond that I will just hit the rev limiter, which is very easy on these dirt roads.

Ron

 

I think it was bad luck reading this yesterday. My voltage just started dropping to 8v while cruising at 2000rpm, revving it up past 2500 makes the voltage raise momentarily.

 

are your belts or belt tight and in good shape?

Ron, sure would like to see a pic of the whole car.....or I could go through the threads and maybe put it all together....NOT!

 

HA HA, your looking at the best parts man !!! :sillylol:
Lets just say, I'm not to the body work yet...

'rezinn' there's a way of checking the voltage regulator. When doing my alternator 101 research I came across way's of sticking a screw driver in the back of the unit. Now this is actually a test hole, that allows you to ground something inside there to the case. This will basicly bypass the voltage regulator. If you see your voltage go up to 15+, then you know your regulator is dead. If that's the case, just rebuild the sucker. Beyond that you can take it to your local auto store & have them check it or replace it.
My Autolight 83amp w/clockwise rotation & life time went for 84 bucks @ Checker Auto.


Ron