TR2/3/3A Battery/Control Box/Voltage Regulator

[HighAltitudeTR3]

I have a slew of questions regarding my VR/Control Box

My voltage with the car off at the battery is 12.86; seems a bit high. When I start the car it drops to a more normal 12.7ish. At my terminals on my CB, (checking D & E per the book) I cannot get a decent read on what is charging and I also cannot get the VR to cut out at any voltage.

I am not sure how to test if the CB is defective... maybe I'm way off on my adjustments. I don't feel like this is rocket science, but maybe someone can simplicity it a tad more for me?

TIA!!

 

[CJD]

The 12.86 means your tester reads a bit high. A lead acid battery will always be 12.6 after it sits for a while, and then will go down from there as it looses charge.

So, if you rev the car to 2000rpm or higher what is your voltage across the battery?

When you say the regulator never cuts out...what are you referring to? After the engine shuts off the regulator has a contact that should open to remove any load from the battery. If it fails to "cut out", the coils in the regulator have a constant draw that will drain the battery overnight.

What is the problem that has you concerned that the regulator is not working?

 

[HighAltitudeTR3]

Thanks John for the response.

The cut out is open when the car is off, so that function works. The cut out never disengages when the car is running, so I am worried the battery will be over charged.

I also don't get the constant chatter from the regulator.

 

[CJD]

Ah...so the vegulator is never kicking the generator on. Hold on, let me refresh my memory and I'll get right back. Randall has all the adjustments memorized, so maybe he'll be here soon too!

 

[HighAltitudeTR3]

And to add...
12.75 when the engine is running across the battery.
My voltage regulator is flashing, but don't know if I'm getting enough separation between the points (or if that is even an issue).
The cut out is supposedly supposed to closer between 12.7 and 13.3 but maybe the battery starting with 12.86 has something to do with the cut out closing immediately?
I also set the VR @ 2000 RPM to 16.58 volts (on the high end, but it's much colder here. Suggested is between 16 and 16.8 @ 68 degrees).

 

[CJD]

OK, I think I'm remembering after looking over the diagrams.

It sounds like your cutout it functioning normally. The cutout contacts should be open whenever the engine is not running. Once the engine is started, the cutout should close...and should remain closed until the engine is turned off. So it sounds to me that your cutout is functioning properly.

So, it sounds like the charging problem is in the regulator side of the control box. First of all, as I said before, chemically a lead acid battery at rest will only show 12.6 volts. If your tester is showing 12.83, after the battery has sat for at least 30 minutes without a charger, then I would mentally note that your tester is off by about .23 volts. That's pretty common...most of my testers are off +- a fraction of a volt. So, with that said, if you start the engine, but show a decrease in voltage at the battery, then it shows the battery is not charging AND is under a slight load, i.e. Probably the ignition.

The next step would be to clean the points in the control box, and then try to adjust the regulator for a charge voltage of between 13.4 and 14.4 volts. If you drive short distances, shoot for the higher side of the range. If you drive farther on the freeway more often, then go for the low side, so you get less water boil off while you charge.

Before I go into more detail, does this seem like what you have going on?

 

[HighAltitudeTR3]

I was just reading about the cut out and it's function. It does seem to be far less adjustable and far less of a need for it.

The regulator may very well be the issue and I am going to start from scratch and set all the gaps again. I have a feeling my gaps are off.

I do drive shorter distances and I think that setting it on the high end is going to be better.

My original concer is the book was suggesting that the cut off would closer when the voltage would reach a certain voltage, I think because this is a relatively new battery, it just shuts off immediately as it doesn't need much charge. Am I getting that right?

 

[HighAltitudeTR3]

I might be flailing here... just rechecked my generator. The voltage drops from the battery when I'm testing it...

electrical issues are my Achilles heel!!

 

[CJD]

You may be confusing the regulator and cutoff functions of the control box. They are actually separate mechanisms, and merely share the same box.

The cutout has one function, and that is to disconnect the generator AND regulator from the battery. As we mentioned above, WHen properly adjusted, the generator will put out at least 13.4 volts when it is turning with the engine. When you shut off the engine, the battery would back-feed the coils in the regulator and generator if there were no means to disconnect the battery...and that is where the cutout comes in. When the engine is turned off, the voltage in the system drops below the 13.4min volts it had when it was turning. So, the cutout needs to be adjusted to open it's contact at 13.3 volts max. It MUST open the contacts by 12.7 volts, otherwise the system will stabilize at the battery voltage of 12.6 volts, and the battery would slowly discharge by back feeding the generator. That is why the book says to adjust the cutout to open between 12.7 and 13.3 volts.

Now, to check the cutout, open the control box and visually look at the cutout contact. It should be open. If it isn't, then physically pull the contact open, as it may have welded closed. If you can then manually close the contact, or it closes back on it's own, and it stays closed...you need to adjust the screw to the point that it does open when you release it. This is all with the engine off.

Now, start the engine. The contact for the cutout may close immediately. If it doesn't, rev the engine to 1500rpm or so and it should close and STAY closed when you let the engine go back to idle. If it opens every time the engine idles, then adjust it to where it just stays closed so long as the engine is running and idling. Your idle must be at least about 750 or more. Below 750 it is common to have the cutout open anyway, until it is reved and the generator steps up the system voltage. If the contacts never close...then we need to check the generator voltage across the "D" and "E" terminals on the box, to make sure the generator is putting out at least 13.4 volts when reved.

So far all the conversation is concerning the cutout only. You can test the cutout actual voltage by testing across the "D" and "E" terminals on the control box.

If the cutout works, and generator voltage is above 13.4 to 14.4 volts at 2000rpm...everything is working as it should.

If the cutout never closes, and the generator voltage is below 13.4 volts at 2000rpm...then either the generator is not functioning or the voltage regulator is not adjusted/working. When the regulator section of the box is working, you should see the regulator contact (different from the cutout contact!) opening and closing at a regular interval while the engine is reved above 2000rpm. Once again, if the contact does not cycle, then either the generator is not working or the regulator is not controlling it.

 

[CJD]

And I do apologize. Randall is the EE major, and usually gives a much better explanation than I do about things electrical.

 

[HighAltitudeTR3]

That is most helpful!! I can say the cutout appears to be functioning, especially after your description of how it's meant to work.

Now I think it's on to the regulator or the generator. I mentioned I have a new generator, but seeing as I ordered it from VB it might not work.

I tried testing the generator with Moss's video on YouTube and I am not sure it's working as it should. I'm also slightly concerned as it says "negative ground" on the side of it. I am running positive ground, but I did polarize it. Not sure if that makes a difference. (Go easy on me if it does).

I'm not sure the regulator clicks/taps like it is supposed to. I can see voltage going threw it as it sparks at the contacts, but I don't see the chatter as it's described elsewhere.

Any good tests for both of these? Probably have to back to square one testing generator, then regulator (andnsomwthing tells me fixing all of this will get my ammeter working again).

I have to apologize - electrical is my Achilles heel when it comes to cars.

 

[HighAltitudeTR3]

I wanted to add... I tested the dynamo backward (hooking power up to the terminals to see if it will work as a motor). And it seems to work fine, I also get voltage out of the back of the dynamo as well.

So I need to determine if the issue is the regulator or the wires or both. The regulator, I have a feeling, is going to be the issue. How do I test it? What is the best process for adjusting it? Also, anyone ever see a video online of one working? I'd like to know if What I'm seeing is correct...

Thank you again!!

 

[CJD]

What voltage do you see across the battery when you rev the engine?

 

[HighAltitudeTR3]

I will double check when I get home. I believe I was seeing 13+

Now I've gone and messed with the Regulator so much, my setting are off and I don't trust any reading.

I will say I just noticed in the Lucas manual the voltage at the terminal is 1.5-3.0 volts. Which is what I get.

I'm so lost, I'm getting over loaded with info. What can I come back with tomorrow to get my Sunday on the right track... I'm either getting this one dialed in or I'm ordering a new control box.

 

[CJD]

That's easy to do! Let's simplify it before you do anything else.

1). Check the voltage across the battery terminals. On your meter you should get about 12.83v.

2). Start the motor and rev it to at least 2000rpm. Now check the voltage across the battery with the engine reved up. You should see 13.4 to 14.4v (on your meter that will likely be 13.63 to 14.63v).

3) if you see the voltages in 1 and 2...then your regulator is set perfect, and the cutout is also cutting in perfectly.

4). Shut down the engine and then look at the cutoff contact. It should now be open.

The above is a quick and dirty test. If you get the voltages and the cutout as noted, then you're golden! If you don't, then let us know what you're actually seeing and we'll adjust from there.

 

[HighAltitudeTR3]

Well the quick and dirty test is giving me some bad signs...

Voltage across battery: 12.81
Running: 12.63



What is going on?!
Now I'm concerned I've dialed and refilled too many times and the entire control box is upside down and backwards.

 

[CJD]

That's great...

Double check to make sure the "D" terminal on the control box goes to the large generator post. The "F" terminal should be on the smaller generator post. The "E" has a good ground to chassis.

1) Next, start the engine and place the tester across the "D" and "E" terminals on the regulator. Take a reading. If it is below 13.4 volts, slowly rev the engine to see if the voltage increases. Do not rev over 2000rpm, and if the voltage rises above 14v immediately stop reving and shut down.

This test is checking the output of the generator as controlled by the regulator. If it produces above 13.4 volts, then the generator is good. If the voltage is in the range 13.4 to 14.4, then the regulator is set correctly also. If the voltage runs away high (above 15 volts) then the regulator is out of adjustment.

2) If you get no increase in voltage as the engine revs in step 1, then we need to test the generator. To do that, you will need a jumper wire. With the engine idling, and the tester still across the "D" and "E" terminals...place a jumper between the battery negative terminal and the "F" terminal on the regulator. Observe the voltage across "D" and "E". It should rise, as you are manually activating the generator fields. Rev the motor SLOWLY! DO NOT REV above 20V! If you get anything above 14, you know the generator is good. Remove the jumper and shut down the motor.

The above steps test the generator for output. If you get no output, then your generator is bad. It will have to be rebuilt or replaced.

If, in the above steps, you get a voltage spike, then your generator is good and we need to test/adjust your regulator.

Let us know how it goes!

 

[HighAltitudeTR3]

Wow, thanks for all of that. So I did step 2 first, started at the generator and then at the VR. (Wanted to make sure I had good wires, I did). Generator is good and charging as it should.

Step 1 was a little more difficult, but I was able to dial in the setting enough so that I didn't feel like my wires would melt with a couple quick joy rides. I ended up ordering the preadjusted one from Moss. I don't doubt the one I have can be adjusted, but it is in rough shape anyway.

The ammeter is still not working, which is strange because it's such a simple mechanism. I am going to see what happens with the new VR from moss and hopefully that fixes that (I'm hoping there is just an unnecessary amount of build up I can't get to keeping it from working).

 

[CJD]

The point contacts to eventually burn, so they make an inconsistent connection. Running an ignition file over them and cleaning with contact cleaner may help extend them.

 

[CJD]

That is interesting about the ammeter. Like you said, not much to go wrong. I guess the spring could break, which would peg it to one side, or the little needle bearing may have gotten gummed with dirt. I see this one on Ebay...

https://www.ebay.com/itm/Lucas-BM4-...%3A7505467215c0abc642b3ae87fffb0e1b%7Ciid%3A2