Alternator SIV Cont...

mxp01 · Oct 22, 2007

I Have done it, I am Negative Earth. I have the Alternator on the car and it works somewhat. But from what i'm getting it seems that the Gen. was putting out much more UMPH (power). I am getting about 13-14 volts running, but as the car runns for a couple secounds the Voltage and AMPS decrease. But it still stays Positive and the Voltage is about 12.8 (with no loads ). When i Turn lights, Panel Lights, Ect... the AMPS Decrease to about -25 amps depending on how manythings are on. When I rev the motor the amps starts to go up (but still stay On the Negative side) if i race the motor i can get the Amps to ZERO out, the Zero Postion on the Ammeter. Is this How it is Supposed to Operate. I read the Alternator Conversion Link, but it didn't explain what the out come.

Any Thoughts
Cade

Nickodell · Oct 22, 2007

No, you have a problem. The main benefit of the alternator vs. the generator is that the it can supply full output a low revs, typically 1000 engine rpm and up, whereas the generator needs much more speed. You shouldn't need to rev the engine to get full amps. My AC Delco puts out 60 amps at 1500 rpm. I'd say the sensor is not working correctly and thinks the battery voltage is higher than it really is with a lot of load on.

Ken Ellis · Oct 22, 2007

Cade, et. al.,
Can you describe the changes you made to the voltage regulation circuit? Do you have a quick link to the specific article you used as your roadmap?

Just as a check, does the ammeter go into negative territory (indicating battery discharging) when you're cranking the starter, before the engine fires? (If it starts "too quick" then pull the 12v coil wire or something to keep it from firing.)

Ken in Columbus

mxp01 · Oct 22, 2007

Ken
This was my map http://www.team.net/www/rootes/sunbeam/alpine/mk1-5/techtips/altconv.html, I did this EXACTLY to those Directions(i used the 1980 Nissan 720 Alternator) I have Triple checked all my wiring also. BUT i have justed recently noticed, Ignition Light does not come on (Has a good Bulb). I will get back to you on the Starting.
Nickodell
At Low rev 1000, i get about 5-10 amps when i race the motor 4500 i get 30-40 amps. Should i use the AC DELCO???

Thank you
Cade

Wombat · Oct 23, 2007

Cade

If the ignition light is not coming on, there is no current going to the field windings of the alternator at startup. This is needed to get the alternator to start producing current. Once it starts, some of the current it makes is bled off to power the field.

Can't offer a specific fix, but look for the cause if the ignition light not working.

Nickodell · Oct 23, 2007

mxp01 said:
Nickodell
At Low rev 1000, i get about 5-10 amps when i race the motor 4500 i get 30-40 amps. Should i use the AC DELCO???

All alternators work the same. Seems as if you may have a faulty one. Remember, if you go checking the field windings, that they are on the rotor (armature), not the frame. This is the exact opposite of a generator, and the reason why alts. can put out tons of juice at low revs, and their rated maximum at not much faster.

If this is not a new, or factory refurb., unit, the brushes may be worn.**

Nick

**Alternators have brushes??!! Contrary to a popular misconception, yes they do.

Tom H · Oct 23, 2007

Cade,

There is one huge issue here. Have you wired this exactly as shown in the drawing in the article you link to? If so, the ammeter is wired WRONG. As wired per the drawing, the Ammeter will only show the current from the Alternator, and not the current to and from the battery as it should. But if it's really wired this way, it would never read NEG unless it's wired in this location but backwards. The B+ terminal is the large terminal on the Alt and is the Output terminal. Current comes FROM this terminal to the battery and the system. Current never goes into this terminal.

See my long post (#19) on the second page of this previous topic:
http://www.saoca.org/protected/forum/showthread.php?t=311&page=2

There is a lot in this thread, and may confuse, but I think my long post does a pretty good job of explaining the ammeter circuit. Especially note the last paragraph. And then check your car with the motor off. Turn the lights on and see what the ammeter reads. If it goes from Zero to Neg as you turn on the lights (as it should if wired properly) then maybe you have the ammeter wired correctly, but then I'm not so sure you have everything else wired according to the original article.

Lastly, you mention current readings from teh ammeter and also Voltage readings. Do you have a Voltmeter wired in , as shown in the drawing also? Or are you using a separate portable Voltmeter for the voltage readings?

Tom H

jumpinjan · Oct 23, 2007

Tom H said:
Cade,

There is one huge issue here. Have you wired this exactly as shown in the drawing in the article you link to? If so, the ammeter is wired WRONG.

Its not necessarly wrong, this is the way that I wire it on the series V. The reason is that shunt is the weakest link in the whole operation of the vehicle. If it blows when wired in the alternator circuit, just the alternator goes down and the car is still operable. The other way, it's completely dead.

Tom H · Oct 23, 2007

When I say "wrong" I mean not the way the factory intended, nor the way most people expect. Jan does have a reasonable point, but if you read the long post I refer to you'll see why that way of wiring it is not so useful. BUT most importantly, the neg readings you describe cannot occur if it is wired as per the drawing. So it is imoportant to understand how it is wired in order to help diagnose your problem.

Tom

mxp01 · Oct 25, 2007

Tom

The way I have the Ammeter wired in is not the same the drawing indicates. The B+ lead on the alternator runs in to a Junction box that I installed. The way I have it all wired is, HOT wire From the Solenoid to the Ammeter, from ammeter to the junction box where it meets B+ from alternator and load. When the car is off and I turn on the lights the ammeter goes to the negative (Hints: Wired correctly???). I am also using a FULLY charged Battery, if that is any help.

Nick

The alternator is rebuilt (O'Reilly's Auto Parts). So with the ignition light not working is it more probable that the alternator is FAULTY. I get negative amps when the engine is cranking, when it fires up the amps are 30+, but after running for a couple of seconds the Amps drop to 5+. When I turn lights, panel lights, etc. the amps go negative. Now the only way to get them to go positive is to rev the motor. As it has been explained to me, the benefit of the alternator is full power or almost full. power at idle, That clearly is not happening for me. By the way, I am using a portable voltmeter.

Cade

Nickodell · Oct 25, 2007

mxp01 said:
The Alternator Is Rebuilt (Oreilly's Auto Parts). So with the Ignition Light not working is it more Probable that the Alternator is FALTY.

Cade

I think O'Reilly must have been having an off-day. I suspect incorrect winding of rotor or stator, but the voltage regulator may be duff as it's only letting lots of amps out when you rev and the voltage rises.

Ken Ellis · Oct 25, 2007

Nick and Cade...
Just a thought -- have you 'triple' checked that the leads from the alternator include the lamp in their loop -- connecting on the switch side of the lamp -- rather than connecting together on the alternator side of the lamp?

I would be tempted to do the following:
Keep the alternator installed in the car, but replicate the circuit externally -- using different switches, lamps, and meters than the ones in the car. Go ahead (for now) and use the car battery, hooked to ground, but you provide direct connection between the components without using the car's wiring. Make sure all connections are secure, because things may get damaged if the alternator becomes disconnected while under load.

And, double check your ground (with a continuity checker) from the battery to the frame, and from the frame to the engine. Couldn't hurt.

Ken

Tom H · Oct 26, 2007

Cade,

Sounds like you're on track. Based on your results so far, it does indeed sound like a faulty alternator, as Nick also suspects.

Ken's thoughts are worth some looking as well. But pulling the alternator and taking it back to where you bought it and letting them bench test it may be simpler. And no need to check the continuity of the ground connection between battery and frame and frame to motor. The fact that the starter can turn over the engine to start it is a better test than any continuity checker coud do.

Tom