Seff

Can it be done? I have an externally regulated alternator and a spare diode trio, is that enough to make it internally regulated?

MDchanic

I'm sure that with a significant amount of fabrication and ingenuity you (as in: You - Seff. Most people couldn't do this) could convert an externally regulated alternator unit to internal regulation, but there is no simple or easy way to do that.

Your best bet is to replace the entire alternator with an internally regulated one. You will also get the option of a higher power output.

- Eric

Seff

Ah. I remembered wrong, then. Thanks for setting me straight. :P

The externally regulated Alt doesn't need a diode trio, does it? Doesn't look like it in the CSM, though it DOES refer to a rectifier bridge. I can take a photo of the Alt to show the parts I have?

I'm going to use this spare Alt and ignition coil on my ****** jeep to make it 12 v, and I'll be running points on it, so no real need for an internally regulated Alt, nor for a high power output. This thing has lights and ignition, that's it. I'll just put a 12 v regulator on it.
Would I need a resistor wire on the ignition like on the Cutlass to run the points? Does this resistor wire also exist on the 6v system, perhaps?

MDchanic

A diode trio and a diode bridge, or bridge rectifier, are all the same thing.
All alternators that produce DC current must have rectifiers to rectify the alternating current into direct current, but the diode assemblies of the internally and externally regulated alternators are different and don't interchange.

Whether your Jeep needs a ballast resistor depends on its coil - look at the coil and see whether the words "Use With Resistor" or something similar are written on it anywhere. If not, you should be able to tell by finding the model number and looking it up.
Essentially, if the coil has a higher resistance, it does not need the ballast resistor.

Most points ignition systems, regardless of voltage, use ballast resistors (and some don't).

- Eric

Seff

Gotcha on the rectifier bridge.

Am I understanding correctly that the use of a resistor is dependent on the coil and not the distributor? Because I plan on using my old coil from my Cutlass, so that answers that...

MDchanic

Yes, it's dependent on the coil. If the coil doesn't have enough resistance, it will draw too much current and overheat - a ballast resistor will prevent this.

In more detail: Making a coil with a lower resistance allows you the option of running it on a lower voltage, such as was done on most cars with points ignition - the resistor is out of the circuit while the engine is cranking, so that if the battery is low, and that voltage is further reduced from cranking, the car will still start.

Further, the coil is part of an LRC (Induction / Resistance / Capacitance) system, in which the correct system resistance contributes to the system reaching the correct resonance or impedance, at a given frequency (ie: engine speed). A ballast resistor is designed to be heat-sensitive, so that as it warms up its resistance changes significantly, tailoring its resistance to the needs of the system.

- Eric

Seff

Well, the engine is radically different from the Olds engine, but the operating temperature is the same, so the resistor wire SHOULD work fine?

I'll bypass it during cranking, of course.

MDchanic

Technically, the Jeep may require a different resistance.

The best thing is to look and see whether you can find a resistance specification in the factory or aftermarket literature.
MOTOR manuals are great for this sort of stuff.

Even Olds used different resistance values for different engines at different times.



- Eric

Seff

...And if I can't find that info on the L-134 ****** Go-Devil engine, I COULD look up the resistor in the existing 6 V wire and calculate the needed resistance from there, yes?

MDchanic

For a low-revving 4 cylinder engine, the exact resistance won't be critical.

Anything around 1.5Ω should be fine. I'd probably buy whatever the standard Chrysler ceramic resistor is and call it a day.
Just check your coil voltage while running with the resistor in series, and make sure it's about 8-9V.

- Eric

Seff

I'll try that.

Seff

In case anyone was wondering, the conversion from external to internal regulator in an old alternator like mine would need a regulator like the one in the link.

http://www.henrikusa.com/produkter/6...1969-til-1991/

MDchanic

Without searching the part numbers, I believe that's the standard internal regulator for an internally regulated alternator, which will not bolt into an earlier externally regulated alternator.

- Eric

Seff

But Eric, that merely a matter of violence!

MDchanic

Or, as the other Eric says, Explosives.

- Eric

Seff

Damn, I used to be a Combat Engineer, I should have thought of that...

Seff

The resistor wire I have from the Cutlass measured at 3 ohm. I DID connect it to a 12 v battery, but the voltage drop was insignificant at best (something like 0.2 v or so). Methinks a ballast resistor is simply easier to install.

MDchanic

Yes, and easier to bypass or mess with, if you ever need to.

- Eric

stellar

The alt can be converted to an internal. There are 2 different styles of the external regulated alt. The one that looks like an internal can be easily converted using the trio and reg, but you will also need to insulate the grounded field brush. External alts are B circuit and Internal alts are A circuit. Basicly A circuit has both brushes insulated and B circuit has one brush insulated and 1 grounded. The early style external would be hard to convert, but anything can be done. This conversion regulator can be used with either external regulated alt. No extra wiring needed. The orange wire is for an indicator lite if wanted, but not necessary to work. All other wires from this conversion reg connect to alt. Very easy setup.

MDchanic

So that "external-internal" regulator goes on the outside of the alternator, on the back, and plugs into the socket on the back, as well as connecting to the ground and the hot post? Very cool.

I hadn't seen one of those. Thanks.

- Eric

stellar

Yep. The one in the pic is attached to the side of the alt by one of the 4 bolts holding the alt together. You cant see the mount hole in the pic. It also has an adjustment for voltage. If you want your voltage a bit higher or lower you can dial it in. There is another style that just plugs in to the alt and sits on the back . No bolts hold it on. The plug is part of the reg, but it is more fragile as the plug in is part of the reg and only secured by the resin on the back of the reg. It costs more also. I prefer the one pictured. It is easy to convert or eliminate wiring problems. Probably not a bad idea to keep one in the glove box for an emergency. If anyone needs them I have them.

Seff

I fired the jeep up Sunday with the resistor wire, coil, ext regulated alt, and voltage regulator out of the spare parts box for the Cutlass. It works flawlessly, except that the ignition switch doesn't turn off the car... Love me some electrical gremlins.

MDchanic

Excellent!

Who needs a switch to turn off the engine, anyway?

Just put your palm down flat on top of the carburetor and it'll stop.

- Eric

Seff

I just yank the choke handle and push the hand accelerator all the way in. Problem solved.

Seff

Alright, so the problem is that there isn't a gen light in the circuit, meaning power flows through the voltage regulator back to the ignition, effectively keeping the engine running. If I wire in a 4 amp gen light, the light stays on and the generator doesn't charge at all. Lost power this way twice.

I never seem to have more than 12.5 V on the battery when the car is idling, though. That can't be right, can it? I was told that if I hotwire the F and 3 terminals on the external regulator, the alternator should start giving me 15+ V, but that didn't happen when I tried. Worn out alternator, maybe?

oldcutlass

The gen light should have voltage on both sides, no ground connection. The alternator should be putting out 14-14.5v at all times.

stellar

what alternator are you using?

Seff

Stellar: Delco-Remy externally regulated 55 amp unit. Identical to the one in the 72 CSM.

Old: I wired the bulb to the "4" post on the voltage regulator. "F" to "F" on the alternator (the one going to the brushes, right?) and the "2" post to the "R" post (the rectifier bridge), and finally "3" to 12 v BAT.

I was not getting more than 12.5 V on the alternator, so I took it apart to make sure that the brushes weren't binding.

oldcutlass

One side of the gen light should be connected to the pink B+ wire under the dash and the other side to terminal 4 of the VR.

Seff

Well, that's what I did. Now both battery and alt show 7.66 V, but the jeep runs fine???

stellar

Seff try a 1/4 amp bulb. or about 4 watts. A 194 bulb is good. Try that and let us know what happens

Seff

I miswrote in the last post - it's a 4 watt bulb I had in the system.

But! I found a fifth terminal under the regulator! Is this the true ground terminal? Because I've been hooking ground up to the housing...


Leg on the right in the picture

stellar

Not a ground. It is for a condenser. Housing is ground.

Seff

Wonderful, then that's off the worry list.

Took the Alt apart again, and half the diodes had broken off the rectifier bridge. Problem found.

Seff

I swapped the new rectifier bridge into the alt. Still not charging properly.

After limping the jeep home on 7 volts (don't ask me how a 12V coil with a resistor wire manages to fire the plugs at 7 volts - maybe I could up the gap a bit?) I swapped the regulator depicted with the original out of my 72 Cutlass - and voila, 14.7-15 V at idle.

Thanks to all for the help.

MDchanic

Has the ALT light gone out?

- Eric

Seff

Yep. Pity in a way, since I was using it as dash lighting... Maybe I'll just remove the alternator belt when I need to see how fast I'm going...