Help On 3G Page

[Gary Lewis]

Machspeed wrote

I'll let the two Jim's respond. We need an "eating popcorn" emoji, cause that about all I'm doing on this ride.

I need you to verify that I made the correct wires red.  

[Machspeed]

Yep, I sure enough did that!

[ArdWrknTrk]

So, where is the power in the lt gr/red wire coming from, if that's what the 'voltmeter' is monitoring?
And in that case, wouldn't it save about 20' of wire in the loop if you just found key-on power under the dash?

[kramttocs]

ArdWrknTrk wrote

... wouldn't it save about 20' of wire in the loop if you just found key-on power under the dash?

Yes  I have thought about this and been meaning to find a scrap cluster plug, removing those two (y/lg and r/o), and seeing what kind of terminals they are.

Or better yet- pull the terminals and some length of wire from a parts truck, swap the existing terminals with those and leave the factory wiring alone.

[Gary Lewis]

The LG/R wire is coming from the ignition switch in both cases.  In the case of the warning light it comes through the light first, and in the case of the ammeter it goes directly to the regulator, as shown below.

And yes, you could shorten the run by finding key-on power under the dash.  But you'd also have to find the wires to the voltmeter under the dash, and they aren't that easily accessed.  Easiest way is to pull the gauges and wire just ahead of the connector.

[kramttocs]

Edited my post after yours Gary but yes - the best way to me would be to remove the wires from the cluster connector and replace them with some from a scrap harness. That way one doesn't chop up their main harness. This all goes back to whether those choosing this option need/care about removing the extra length.
While I may be interested and would like to test, it's not something I am rushing out to do.

[ArdWrknTrk]

I'm just saying, if you're monitoring voltage from the ignition switch,
power starts at the fender relay, goes through C610 to the ignition switch, out the lt gr/r hot in run 'I' wire, gets tapped into C610, to the meter, back to C610 and then to ground.... somewhere.

That's insane.

The switch is on the column and the hard point for ground is right by the radio.

[Gary Lewis]

While I think this approach would work fine, I doubt anyone would really do it.  To me you are either looking for accuracy, in which case you'll monitor the battery via a relay, or ease of installation, in which case you'll connect the LG/R wire to the R/O wire and ground the Y/LG wire.  Done.

Saying it another way, why go to all of the work to tap into the meter circuits at the cluster connector only to monitor the changing voltage in the cab?  It seems like a lot of work to get mediocre results.

[ArdWrknTrk]

I was never the one to suggest using the voltmeter for cab power.
In fact, the only way I got drawn into this was because I'd suggested to John (quick and easy) that he tap his HO choke relay if he wanted to monitor battery power. (The fuselink literally sits on the same stud with the battery cable)

[kramttocs]

Agreed Gary. I've definitely given it thought and while I'd would like to try it for a comparison just to have the data to see what kind of drop there is, it goes against the reason for the LG/R+R/O option.

[kramttocs]

I don't think anyone is saying you are.

I mentioned it early on because, while admittedly I hadn't given the drop much thought when I installed it since all the aftermarket voltmeters I've installed use a key on source directly, it does work and is easy...but so on and so on and scooby dooby doo-bee

[Gary Lewis]

There are so many different ways to do it, each with their own advantages and disadvantages, that we could debate it ad nauseam.  Oh wait!  We already have!  

So I'm planning to continue with the options we have.  They may not be the best ways, but they are reasonable ways.  

Given that, I'd like to have help making sure I get these alternatives explained correctly.

[Machspeed]

Gary, Jim brought something up that rather faded among the numerous comments. Would it be possible to set up the schematics and maybe even the pictures in a printable format?  

[Gary Lewis]

Maybe.  But what format would be printable?  The schematics are in jpg format, and you can right-click any one of them and do one of several things.  When I right-click I see the options below.

Are you thinking there ought to be a "Print" button?  I don't know how to do that.  Maybe someone on here does?

[Machspeed]

Sorry Gary, cancel that request. I was on my tablet trying to print it and I can't. I can, however, print it off my desktop. Thanks!

[Tyler]

Frustrated with myself.....starting to regret the 3G endeavor.  Didn't do enough research to ensure the new LRC regulator had the same plug design. They are both supposedly from the same year span.
If you know what specific vehicle I need to find at the JY in order to source the correct pigtail from, please let me know.  I bought a Motorcraft LRC regulator part # F5RU-1036-AA.  Also, I have no idea if this regulator will fit on my DB Electrical 0028 130amp alternator and I'm reluctant to remove the regulator that it came with to verify fitment.  (Not sure if I can get it reinstalled if the new regulator I have doesn't fit.)

[ArdWrknTrk]

Oh! That's got to be frustrating.  😖

So you have the D shape pigtail, and now you have the rectangular shaped socket on the new regulator?

I will say, yes it will fit your alternator.
2G & 3G regulator/brush holders all fit the same in the back of the unit.

[Tyler]

https://smithcoelectric.com/products/8050-514-new-regulator-for-ford-3g-alternators-lrc

I just ordered this one.  Has 2.5 second LRC with proper "D" shaped plug.

Update: No more squealing on startup!  Slightly lower voltage than the original regulator but stays at 14 volts.

[Gary Lewis]

Ty - Sorry you had that problem.  But you appear to have it sorted.  

John - Check out the page now.  I made a few changes to the pic showing where to cut your harness, as shown below.  Does that help?

Still don't have the "this wire does that" info on it, but let's get the cutting right first.

[Max Capacity]

Sorry to be late to this thread, but reading back on Feb 15 2012 @4:41PM Jim wrote,

"On a 1986, with a 2G ALT, if it fails and you pick up a replacement 2G at the auto parts store, it will NOT work if you only have 2 wires on your wire regulator plug. You will have to replace the plug with a 3 wire plug to get it to work."

I'm that guy. On Nov 28 2021 I got a replacement 2G ALT from a long time auto parts store, they swapped over my V belt pulley and the ALT was plug and play into the 2G, two wire VR harnesses. My 86' 302EFI, has two wires, yellow/white and green/red next to each other on the VR plug.


Also, the charge indicator gauge in my truck has always worked well.