BCM Community

Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: irstaxhelp on April 22, 2011, 03:33:59 PM

Title: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: irstaxhelp on April 22, 2011, 03:33:59 PM
Okay so there are three wires going to the generator.  Can anyone tell me what they are.  The large one is power and black must be ground.  What is the green wire.   I just replaced the generator and it is not charging. 

I was also scared to death to open the voltage regulator.  I did though and is there some book on this thing?


Thank you John
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: gus on April 22, 2011, 04:33:16 PM
Do you have a maintenance manual?

The wiring diagrams are all there. If not I can email you some copies I got from Dallas.
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: zubzub on April 22, 2011, 05:12:14 PM
I'm guessing you changed the generator because you had no charge.....are you sure it was the gen and not the voltage regulator?  Trouble shooting the 4104 gen and V reg is pretty complicated.....after Gus sends you the maint  manual and you have settled in and had a nice long read, maybe you can work it out.   I didn't even try, read the section, noticed I didn't have the usual Gen or the the same V reg as the manual (I had a twin field Gen) and some kind of after market V reg and now I am "trying " to install a belt driven Alt.  We'll see how that goes as I have already hit a road block.
Anyhow just to say I have messed around a bit with gen and V regs on old cars etc....and I kind of can't stand 'em so i always pull em and install Alts the painless source of DC.  Stay tuned though, I am documenting my switch over to Alt  and will post it when it is done.
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: fe2_o3 on April 22, 2011, 06:27:54 PM
ZubZub...Did you get the "How to" for that alt change, or are you playin it by ear?...Cable
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: zubzub on April 23, 2011, 02:06:06 AM
Gus sent me some pics of his install, but that's about it.  Any info appreciated.  I have a pulley drive with matching internal gear that mounts on the engine. 1st problem old thin drive gear on engine has larger bolts, mine (internal gear that mounts on the engine) need to be drilled out aprox 1/16" larger.  This reduces the wall of the star shaped gear......need to post pics, I'll start a new thread.
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: irstaxhelp on April 23, 2011, 08:49:50 AM
I do not have the manual so pls send !

I got a quote for $1100 for setup alternator system from HB Industries

Here are the instructions to convertftp://71.0.42.153/Tech%20Support%20Transfer%20Folder/SDavis%20Files/4104%20manuals/GMC%20PD4104%20Alternator%20Conversion%20and%20Positive%20to%20Negative%20Ground.pdf (http://ftp://71.0.42.153/Tech%20Support%20Transfer%20Folder/SDavis%20Files/4104%20manuals/GMC%20PD4104%20Alternator%20Conversion%20and%20Positive%20to%20Negative%20Ground.pdf)

ftp://71.0.42.153/Tech%20Support%20Transfer%20Folder/SDavis%20Files/4104%20manuals/GMC%20PD4104%20Alternator%20Conversion%20and%20Positive%20to%20Negative%20Ground.pdf
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: irstaxhelp on April 23, 2011, 08:53:52 AM
So I should convert you think!
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: Len Silva on April 23, 2011, 09:03:40 AM
Here are the manuals:
http://manuals.lenstudio.com/ (http://manuals.lenstudio.com/)

I definitely think you should convert to a modern alternator.  I doubt that you will find a shop anywhere that has seen or worked on one of these systems in at least twenty years.
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: zubzub on April 23, 2011, 10:30:37 AM
The link for the conversion didn't work for me.
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: Cary and Don on April 23, 2011, 11:29:19 AM
We changed the voltage regulator in our 4107 12 volt system.  It was easy and the board was under $100 at the time.  We didn't know we weren't charging until we ran our headlights.  Good thing we had a charger and our gen set was on the house batteries.  There were three wires,  red to hot, white to field, and black to ground, as I remember.  The generator has the terminals labeled on it.  Adjusting the output was done by a screwdriver.  The manual was easy to follow.

Don and Cary
1973 05 Eagle
GMC 4107
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: irstaxhelp on April 23, 2011, 02:37:14 PM
I need this manual I guess.  I also only have three wires going to my generator
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: fe2_o3 on April 23, 2011, 03:21:42 PM
According to what I have here. From the reg I have 3 wires to gen. All black but different sizes. It has a #14 from field gen. to field reg. A #00 from arm. gen. to arm. reg. And a #00 from ground gen. to ground reg. It says all terminals are marked. How ever 50 years of abuse and previous owners could alter anything. I hope this helps. ..Cable
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: gus on April 23, 2011, 04:08:49 PM
I don't have the complete manual copy files, what I do have is copies of the electrical diagrams which I am sending to irs. I'll also send to you, zub, if you like.

All I sent earlier to zub was photos because that is what he asked for.

I also have an original 4104 VR which is free to anyone for the cost of shipping. I have no idea if it works, it was bypassed and left in when the pulley driven alt was installed.
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: Len Silva on April 23, 2011, 04:13:47 PM
The entire manual along with the wiring diagrams is in the link I posted.
http://manuals.lenstudio.com/ (http://manuals.lenstudio.com/)
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: zubzub on April 23, 2011, 04:50:04 PM
Thanks I have the all the manuals etc....but if you read the section on the VR you will wish you hadn't.
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: irstaxhelp on April 23, 2011, 05:22:59 PM
Thank you I will check it out so say a prayer for me!
Title: Re: 1960 GMC 4104 wiring diagram needed and help with Voltage Regulator
Post by: gus on April 23, 2011, 05:57:10 PM
OK, since Len has everything on his link I won't send any by email. I probably got mine there in the first place!