is 1-year old 6v Optima going bad?

[Chuck House]

Dave, no, if you leave both D+ and DF open, you will only get a very small voltage. The generator needs current in the fields (DF) to put out the intended voltage. Joe Leoni's troubleshooting guide is excellent and I suggest you just follow it exactly to test the generator and test/adjust the regulator. For example, his test above forces the generator to its max unregulated output (isolated from regulator). Note the 1200 rpm and the comment to only jumper across D+ and DF just long enough to read the meter as the generator is unregulated and you don't want to overstress/overheat it. Good luck.

[Michael Branning]

Dave, no, if you leave both D+ and DF open, you will only get a very small voltage. The generator needs current in the fields (DF) to put out the intended voltage. Joe Leoni's troubleshooting guide is excellent and I suggest you just follow it exactly to test the generator and test/adjust the regulator. For example, his test above forces the generator to its max unregulated output (isolated from regulator). Note the 1200 rpm and the comment to only jumper across D+ and DF just long enough to read the meter as the generator is unregulated and you don't want to overstress/overheat it. Good luck.

Leoni’s info is here:
https://porsche356registry.org/content. ... _id=508436

[Dave Wildrick]

I used Leoni's method from one of his earlier posts to test the generator:
"Lift the D+ wire at the regulator.
Connect a test bulb or voltmeter between D+ on the generator to ground (D-).
Start the engine.
Run engine up to 1200 to 1400 rpm.
The bulb will be very bright or even burn out, that is if the generator is
working.
The voltmeter will read above 7 volts."

Doing this, I got very little output from the generator, which is consistent with it not working right.
Why would he say to do this if it's incorrect?
If the battery is good, and the regulator is good, the only other actor in the system is the generator.
Otherwise, my battery should not have discharged down to nothing during the Hill Country Rallye, where I drove nearly 1,000 miles this past weekend.
I didn't drive at night, so no lights on; I occasionally used a radio (powered by a 6 to 12V convertor (only switched on when using radio).
I don't get it.

[Dave Wildrick]

Dave, no, if you leave both D+ and DF open, you will only get a very small voltage. The generator needs current in the fields (DF) to put out the intended voltage. Joe Leoni's troubleshooting guide is excellent and I suggest you just follow it exactly to test the generator and test/adjust the regulator. For example, his test above forces the generator to its max unregulated output (isolated from regulator). Note the 1200 rpm and the comment to only jumper across D+ and DF just long enough to read the meter as the generator is unregulated and you don't want to overstress/overheat it. Good luck.

Leoni’s info is here:
https://porsche356registry.org/content. ... _id=508436

O.K. I've downloaded it.
Thanks.

[Chuck House]

Dave, I'm not saying your generator isn't bad. It probably is. I was only referring to the last thing you posted which seemed to say you disconnected both D+ and DF and ran the engine. You'll only get a small voltage from residual magnetism in the fields in this instance so that is not an adequate generator health test. I do not know what post you're referring to or the context but I would never say Joe L. was wrong. He was quite the old school analog guy. Doing the bulb test is a quickie if you don't have a voltmeter but the regulator has to be doing enough of its job to supply current to the DF terminal for this to work. If the bulb lights bright, then your generator should be good. It it doesn't, that doesn't necessarily mean your generator is bad. Following the steps in Joe's troubleshooting guide will nail it down.

[Brian R Adams]

I have had recent problems with the red top optima battery in my Ford GT. The first factory one lasted from 2006 to 2019, the second one 2019 to 2020 and not the third good so far. I had heard that when they transferred production to Mexico the batteries went down hill

One could say the quality "went south".
-

[Dave Wildrick]

Dave, I'm not saying your generator isn't bad. It probably is. I was only referring to the last thing you posted which seemed to say you disconnected both D+ and DF and ran the engine. You'll only get a small voltage from residual magnetism in the fields in this instance so that is not an adequate generator health test. I do not know what post you're referring to or the context but I would never say Joe L. was wrong. He was quite the old school analog guy. Doing the bulb test is a quickie if you don't have a voltmeter but the regulator has to be doing enough of its job to supply current to the DF terminal for this to work. If the bulb lights bright, then your generator should be good. It it doesn't, that doesn't necessarily mean your generator is bad. Following the steps in Joe's troubleshooting guide will nail it down.

Here's the Leoni post that I followed:

Charging problem
#1 Post by Shawn Wilson » Tue Jan 13, 2009 2:29 pm

Is there a way to find out why my battery is not charging correctly. I swapped over to 12 Vt and have the "original Look" 12vt regulator and a 12vt generator from NLA along with correct battery. For some reason I get 12v back to the battery, but I maybe reading the charge of the batter and not from the generator (Back feeding). When I remove the lead + strap from the battery why the car is running it dies. How do I trace the problem (Generator/Regulator/Battery) problem
Top
Joe Leoni
356 Fan
Posts: 260
Joined: Fri Mar 14, 2008 6:47 pm
[Charging problem
#2 Post by Joe Leoni » Tue Jan 13, 2009 3:14 pm

Shawn,

What about the red light?
This tells if the generator is above battery (12.6v).

Lifting the + terminal at the battery is not a valid way to check charging.
With the generator there is no output at idle.
Now, this works for the alternator, but there are others that said, "don't
do this with our alternator".

With that said, you are safe by not doing this at all.
And it has no meaning with a generator.
You can make it work, but you need to know what you are doing.
Me, I just look at the red light.

Lets test the generator first.
Did you flash the field after installing.
This you must do to establish some magnetic flux in the field poles.
Here is how to do this, by motoring the generator..
Belt off, Ground DF (to D-)
Apply +12v to D+. Get the +12 from B+ on the regulator.
The generator will motor in a CW direction.
It can motor even if though it might not generate.

So the generator now has the field flashed.

Mount the fan belt.
Lift the D+ wire at the regulator.
Connect a test bulb or voltmeter between D+ on the generator to ground (D-).
Start the engine.
Run engine up to 1200 to 1400 rpm.
The bulb will be very bright or even burn out, that is if the generator is
working.
The voltmeter will read above 14 volts.


Now the generator is proven, or not.
.
Lift the DF wire at the regulator.
With a test bulb (12v), don't use the burned out one, touch between B+ and
DF
on the regulator.
If the contacts are good, the bulb will be bright.
If not the regulator contacts need attention.

Now you will know what is working, or what isn't.

That is it.
Joe]

However, I failed to notice that Joe subsequently added the following post:
[#3 Post by Joe Leoni » Tue Jan 13, 2009 3:03 pm
Shawn,
On the part where the engine is run up, leave the DF grounded from the
preceding test.
This turns the generator on full.
Joe]

This explains why I missed the part about leaving the DF wire connected--as you describe as being necessary when measuring generator output!

[Al Zim]

Usually we furnish a special screwdriver ZIMZ has manufactured with the correct size to hold the inside pulley. I am sorry you were overlooked.
Take the battery out of the car and put it on a 6 volt charger. The reason for removal is so the battery will not gas (corrosive) in your trunk. After it is fully charged (or so you believe) Replace it. Snug the cables Turn the headlights on If the battery is good they should burn brightly for at least a half hour. I believe the battery is bad and this will not happen. Optima usually has a 2 year free replaceable warrantee. I will put 2 screwdrivers in your other car. al

[Dave Wildrick]

Usually we furnish a special screwdriver ZIMZ has manufactured with the correct size to hold the inside pulley. I am sorry you were overlooked.
Take the battery our of the car and put it on a 6 volt charger. The reason for removal is so the battery will not gas (corrosive) in your trunk. After it is fully charged (or so you believe) Replace it. Snug the cables Turn the headlights on If the battery is good they should burn brightly for at least a half hour. I believe the battery is bad and this will not happen. Optima usually has a 2 year free replaceable warrantee. I will put 2 screwdrivers in your other car. al

Hi Al,
The problem is not that I have the wrong screwdriver. The problem is that the pulley you guys put on the generator has notches that are half as deep as those on the pulley on my other 356. The notches are so shallow that you can't get enough purchase on the inside pulley with a square shank screwdriver to hold it in place without shearing off the corners of the notch.

I'll try the headlight test of my Optima; it says on it that they have a 3 year warranty.

Another issue is with the generator you installed on the motor Aaron rebuilt. Along with trying Joe Leoni's methods for testing the generator, I tried the method suggested in the Registry magazine by Geoff Fleming. He said to warm up the motor and then lift the negative battery cable from the battery while the motor is running.
I first tried this at 800 rpm idle, and the motor died, which was no surprise. I then tried this at 2000 rpm, and the motor still died immediately, which indicates that the generator is faulty.
I spent a lot of money on the motor rebuild during which you folks replaced the generator with this one, which now only has a few thousand miles on it, at most.
I will remove this generator and send it to you in exchange for a good one.
Thanks,
Dave

[Al Zim]

Dave: I can fix your car without your having to do any serious mechanical work! You do not have to move the car. As you know I have had my posts deleted for being a doom and gloom guy! I will call you after lunch or you can call me here. DO NOT TOUCH ANYTHING TILL WE TALK. al zim

[Dave Wildrick]

Follow-up to my last post on this thread:

I have determined that my original Big Black Box 6V voltage regulator is not working right, which is the reason my 6V Optima battery went dead after the last trip to the Hill Country Rallye in Kerrville, TX. When I measured the voltage between B+ and ground (w/voltmeter), I never saw higher than 6.0 volts no matter how high I revved the motor. When I did the same on my 65C coupe, I got 6.3 volts at 800 rpm and it climbed almost to 8 volts when really revving the motor.
So, I need to get the voltage regulator rebuilt. I'll probably contact Doug Darrah for that.

In the meanwhile, I noted on an earlier thread on 356talk that someone suggested possibly substituting a 6V Delco regulator for the old big black one. These seem to be used on late '40s and early '50s cars and some tractors. Here's a link to what I'm talking about: https://brillman.com/product/6-volt-del ... 2-42-amps/

These go for just under $90. For that price, I thought I might experiment with one (until I get my old reg refurbished), but I don't want to destroy anything.
Has anyone out there actually tried to use one of these on a 6V 356?

[Mike Wilson]

Keep us posted on the Delco regulator. Always good to have options.

Mike

[Tim Splaine]

Hi Dave, Moss have some great videos on youtube for testing your generator, and regulator. I'm currenly having issue with mine too.
Tim

https://www.youtube.com/watch?v=RjLW_eb3D-c&t=316s

https://www.youtube.com/watch?v=tSJxCNLgL2w

https://www.youtube.com/watch?v=VwMn-5NV5eM

[Tim Splaine]

Just an update. Since I added these useful testing YouTube videos above I have been told by other members that the testing of the Generator won't work on a 356 Generator because it is wired differently to the British cars. For more help on testing a 356 generator, lookup pages 60-61 of magazine 40-2. An excellent article written by Chuck Allard

[Rudy Bernhard]

Dave,
Hopefully someone can just adjust the mechanical contacts on your voltage regulator. If they determine there is something else wrong with it that is unfixable, make sure you get it back. Even the frame is useful. I found this not long ago as a way to revitalize these parts.
http://www.mbzponton.org/valueadded/mai ... ulator.htm
http://www.dynamoregulator.com/
last link is for the current owners of the business.
love that they do 6 volt and custom amps if you contact them.