Positive ground conversion

[Ndill91]

I bought a 1959 b61 thats partially converted to 12v neg ground. The truck is all original for the most part besides the dump body. I’d like to keep as much original equipment in the truck as possible. I had the generator rebuilt because the armature was ceased and the guy tested the regulator and said it was bad. So my question is, if I get a new regulator will this setup work with 12v neg ground just to charge the batteries or should I do an alternator conversion 

[doubleclutchinweasel]

On 9/7/2020 at 10:10 AM, Ndill91 said:

I bought a 1959 b61 thats partially converted to 12v neg ground. The truck is all original for the most part besides the dump body. I’d like to keep as much original equipment in the truck as possible. I had the generator rebuilt because the armature was ceased and the guy tested the regulator and said it was bad. So my question is, if I get a new regulator will this setup work with 12v neg ground just to charge the batteries or should I do an alternator conversion 

Did you ever figure this out?

I have never swapped a generator equipped piece from pos to neg ground, so I am not sure if that would work or not.  But, my R just had an alternator put on it (integrated regulator).  Cables were swapped and it worked.  Only thing I had to do was replace the volt meter.  Original was a single post, so there was no way to "reverse" it.  I put in an aftermarket 2-post unit, so I could reverse the polarity at the gauge.

I'm not sure, but there should be a way to either make that regulator work or there should be a similar neg ground regulator that would work.

Curious what you figure out.

Edited October 13, 2020 by doubleclutchinweasel

[Freightrain]

You can use a generator to charge negative ground power.  Just need to have the polarity set on the generator>  There is a sequence to follow to do this.  Besides that, it should be no big deal.  I know most just put an alternator on just because it's easier(I did).

[doubleclutchinweasel]

On 10/13/2020 at 2:41 PM, Freightrain said:

You can use a generator to charge negative ground power.  Just need to have the polarity set on the generator>  There is a sequence to follow to do this.  Besides that, it should be no big deal.  I know most just put an alternator on just because it's easier(I did).

Good info, Larry.

[Freightrain]

Found some reading for anyone that wants to know how to do it:

http://starautoelectric.com/instruction-for-polarizing-generator/

 

In all the years I have been in business, I have heard many versions on how to polarize a generator and voltage regulator. Some versions are correct, others are totally wrong. 
Polarization is a procedure which matches the polarity for the generator and the voltage regulator. The majority of the vehicles are manufactured negative ground although some of the older vehicles were manufactured positive ground. The generator has to be set up for either polarity. The generator will charge either way, however the voltage regulator has only one polarity. Whenever the battery is disconnected from the vehicle for any reason the polarization procedure should be performed. 
The recommendation on how to polarize a charging system is the following: After the installation of a battery, generator or voltage regulator follow these procedures. The terminals on the voltage regulator are labeled with letters and this is where you will do the polarizing procedure. Both of the components will have battery power so do not start the vehicle or turn on the ignition switch before polarizing them. You will need a small piece of wire fourteen or sixteen gauge with alligator clips on the ends. Find the “B” terminal on the regulator and attach one of the alligator clips, find the “D” terminal and touch the terminal with the other alligator clip. You can touch the terminals a few times and it will produce a soft light spark. Under no circumstances touch the “F” terminal or any other part of the regulator or you could damage the regulator. 
For the Lucas voltage regulators that have the teminals labeled A1, A, F, D, E, the polarization procedure is the same however the terminals that will be used are the “D” terminal and either the “A” or “A1” depending on which teminal is used on the vehicle. Either terminal can be used if wires are going to both terminals. 
Start the vehicle and you should see the red generator light go off on the instrument panel, you may have to rev the engine up a few RPM, generators have a tendency not to charge at idle speed. If you have a gauge on the instrument panel the gauge will respond accordingly. 
Look for more technical information in the future on these page. 

[doubleclutchinweasel]

Great post.  I remember having to polarize regulators on old VWs I worked on as a kid.  Couldn't have recited that from memory now, though, if my life depended on it!

Thanks, Larry.

[Full Floater]

On 10/13/2020 at 9:25 AM, doubleclutchinweasel said:

Did you ever figure this out?

I have never swapped a generator equipped piece from pos to neg ground, so I am not sure if that would work or not.  But, my R just had an alternator put on it (integrated regulator).  Cables were swapped and it worked.  Only thing I had to do was replace the volt meter.  Original was a single post, so there was no way to "reverse" it.  I put in an aftermarket 2-post unit, so I could reverse the polarity at the gauge.

I'm not sure, but there should be a way to either make that regulator work or there should be a similar neg ground regulator that would work.

Curious what you figure out.

Did you have to do anything else to the truck besides the volt meter and alternator?

[doubleclutchinweasel]

On 8/19/2022 at 12:45 AM, Full Floater said:

Did you have to do anything else to the truck besides the volt meter and alternator?

Could not get the fuel gage to work.  Not sure if that was due to the polarity or not.

like I mentioned earlier, the cables were swapped at the starter.  Otherwise the starter would turn the wrong way.

All the lights were fine.

Used the internal regulator in the alternator, and left the old regulator unhooked.

It was really not much of a big deal.

[Full Floater]

2 hours ago, doubleclutchinweasel said:

Could not get the fuel gage to work.  Not sure if that was due to the polarity or not.

like I mentioned earlier, the cables were swapped at the starter.  Otherwise the starter would turn the wrong way.

All the lights were fine.

Used the internal regulator in the alternator, and left the old regulator unhooked.

It was really not much of a big deal.

Thank you for your response.  I think I might go ahead and convert one of mine that im working on.   

[doubleclutchinweasel]

On 8/22/2022 at 5:47 PM, Full Floater said:

Thank you for your response.  I think I might go ahead and convert one of mine that im working on.   

Let us know how it works out.

Like the man said, "I learn from the mistakes of people who took my advice."

[67RModel]

If your objective is to just replace the generator with an alternator its not necessary to convert the entire truck's electricals to over to negative ground. One of my trucks has  an alternator charging one 12V battery on each side. But the whole truck is still positive ground. Originally it would have had positive ground 6V batteries on each side hooked up in series to make 12V and then the two sides connected in parallel to provide enough amps and 12V. The previous owner did the alternator conversion. So I guess my point is the truck can have an alternator conversion done without changing over to negative ground.