Help On 3G Page

[Gary Lewis]

I hope it'll be in the garage!  'Tis 17F here now, so maybe 19 at your place?  Did you get the ice?

[Machspeed]

Ohhhh definitely! I've got heat out there too. I do have one question, what is this sensing wire.....color and location, please? It's not labeled on the harness as sensing wire, perhaps another nomenclature though.

[Gary Lewis]

Sorry, the "sense" wire is the Y/W wire.  It is how the regulator senses what the battery voltage is.  It is the feedback link to the regulator so it can control the alternator's output voltage.

As shown below, which is from the '96 EVTM, Ford attached it to what I've called the megafuse, but in the '96 EVTM it is Fuse Link J.  Jim has recommended that we wrap it back and connect to the output stud.

[Machspeed]

Very good on the sensing wire, may want to label somewhere and describe as you have to me in this thread.

Something else in regards to the wires on my harness and their respective colors. I have three yellow wires each of different gauges. They are solid yellow, no other markings I can find. Also, the red/orange wire is just red, no orange. Is it possible I removed the minor markings when I cleaned them?

On the yellow wires, I may have to go by gauge instead of color.    

[kramttocs]

Cleaning or just natural fading. The secondary colors on the one I cut up are very hard to see also. You can use which splice they go into, length, and what other wires they go into the splice with in addition to the gauge as clues.

Gary's photo should help: http://forum.garysgaragemahal.com/Help-On-3G-Page-tp86569p86819.html

[Gary Lewis]

Scott - Thanks.

John - Scott is right, there really should be tracers on all but the big wire.  But they are sometimes really hard to see.  I know this is your picture, but maybe you can look really closely and find the traces?

And, I could add what the wire does to the pic.  Is that what you mean?

[Machspeed]

Gary Lewis wrote

Scott - Thanks.

John - Scott is right, there really should be tracers on all but the big wire.  But they are sometimes really hard to see.  I know this is your picture, but maybe you can look really closely and find the traces?

And, I could add what the wire does to the pic.  Is that what you mean?

I inspected that harness last night and found no second markings. They are just yellow. Agree, I can determine which is which by where it goes though.

[ArdWrknTrk]

John, is your regulator plug marked ISA on the plug itself?

It's probably best to be referring to these wires by their proper terms of ignition, stator and alternator as that's how a 1G regulator plug is marked.
While charge, exciter and sense say something about their function it doesn't jibe with a shop manual.

But maybe my suggestion for foolproofing just makes it more confusing???
We all know 'dumbing it down' will ultimately prove there is a bigger dummy out there (somewhere)

[Machspeed]

Jim, I'll look when I get home tonight. Thanks buddy!

[grumpin]

85lebaront2 wrote

The real issue with it, the 2G goes full output with no place to really load it down, if it doesn't fry every electronic piece on the vehicle, it can still set itself on fire like a Vietnam era Buddhist monk.

I’m sorry but that cracks me up!

[Gary Lewis]

Jim, you are probably right that we should use the terminology in the shop manual, schematics, etc.  However, there's nothing to say we can't do both.  So here's a stab at that:

LG/R: I for "Ignition" is the official term, but "exciter" is also used in our conversations

W/BK: S is for "Stator" and I don't know what else to call it but that

O/LB: F is for "Field"

Y/WH: A may mean "Alternator", but it is the "sense" wire into the regulator, the wire that lets it determine what the output voltage is

BK/O: Our schematics show the output cable from the alternator as BK/O, but as you pointed out, Jim, not all of the harnii that people might get use that color wire.  As for what to call it, is it "Charge"?

[ArdWrknTrk]

You well know that my brain doesn't work quite the same way as most.  

I think I'd refer to the bk/or wires as output, but charge makes sense as well.

The biggest thing is getting everybody on the same page, regardless of their level of understanding.  💡
If the plugs are already labeled it's probably best to go with that and lessen potential confusion.

[Machspeed]

Gary Lewis wrote

Jim, you are probably right that we should use the terminology in the shop manual, schematics, etc.  However, there's nothing to say we can't do both.  So here's a stab at that:

LG/R: I for "Ignition" is the official term, but "exciter" is also used in our conversations

W/BK: S is for "Stator" and I don't know what else to call it but that

O/LB: F is for "Field"

Y/WH: A may mean "Alternator", but it is the "sense" wire into the regulator, the wire that lets it determine what the output voltage is

BK/O: Our schematics show the output cable from the alternator as BK/O, but as you pointed out, Jim, not all of the harnii that people might get use that color wire.  As for what to call it, is it "Charge"?

This is good, Gary. In some of your discussion in this thread alone, you gents are using terms that mean the same thing but yet are confusing to a guy like me.

BTW, Gary/Jim, I bought the Painless kit and was going to send it back but I think I'm going to keep it and use it for my conversion. It is very high quality stuff. I want only to cut into the alternator side of the harness connector and hide splices  and clipped wire under the plastic wrap that covers the wires. I'll not be using the supplied Painless crimp connectors to join the wires, rather soldering them and putting heat shrink over the solder. I may lay it all out on the bench tonight for a better visual and take some pics.

Gary, you asked me about the ice....little to no ice here. We got lucky here. Icing began north of us in Broken Arrow. Suspect your roads are a mess.

[ArdWrknTrk]

So, you'll be needing the lt gr/red wire and the large yellow cab power wire for now.
What will you be doing with the red/orange and yellow/green wires for your ammeter?

I guess it doesn't matter a bit if you've already removed the ammeter to have it converted.

What does Painless offer for charge cable terminations, to and from the Megafuse?
Are these solder pellet lugs (like RJM) or do you need a heavy crimper for them?

Fwiw, my Amazon recommended popped up with an Iwiss lug crimper last night.
They must be frustrated with me not buying things lately.

[Gary Lewis]

On the voltmeter wires, I've been working on the tabs for that, as you can see on the Voltmeter tab here.  And I believe we should recommend these two approaches:

Monitor Cab Voltage: Take the easy way and use the LG/R to power the voltmeter.  Granted that will give you variable voltage that won't be quite what the battery is seeing, but it won't be bad either.

Monitor Battery Voltage: Use a relay, but don't use the 351HO choke relay, for two reasons.  First, as the other Jim pointed out, if the alternator fails the relay won't get pulled in and the voltmeter won't read.
 In some ways that is good as it'll be more likely to get your attention, but if you really would like to know what the battery's voltage is you are out of luck.  And the other reason is that we'd still have to outline another relay approach for the other folks that don't have a 351HO, so why not do one for all?

That's what I'm working on, so if y'all disagree please tell me a better approach.  And, by the way, the Monitor Battery Voltage tab is using an old schematic that will get updated.

[ArdWrknTrk]

Isn't the voltmeter not reading exactly what you'd want as an indication of alternator failure????  

I mean, I have an idiot light, but for someone without, are you really going to notice the reading creeping down in time to avoid trouble?

I guess some people would want a more granular indication, and without bells and sirens.
But then, it seems downright stupid to me to have a meter showing cab voltage too..

[Gary Lewis]

So you are saying that having the voltmeter go dead if the alternator fails would be similar to a warning light?  That does make sense to me.

If we were to recommend using a relay to ground the negative side of the voltmeter then it could be either the 351HO's choke relay or a similar relay for non-HO trucks.  That would make it easier to put together the package.

As for measuring cab voltage, while I agree that the best approach is to measure battery voltage, I do know of plenty of people that don't seem to care.  So for them I'm ok to give them a way to do it.

So, folks, please give me your thoughts on the relay approach.  Run it off the stator output so it might go dead if the alternator fails?

[ArdWrknTrk]

I said at the top of the last page, I can't have any opinion on how somebody else decides to implement an upgraded alternator...

I think reading cab voltage is *not wise*, and I certainly think not having obvious indication of a charging failure is *not wise* either.
But note, those are my thoughts, and I just pointed out that my brain is different.
I'm not saying that someone who makes different choices is *not wise*, though the thought does quickly cross my mind.

If you didn't want the stator to trigger a relay you could always tap the same ltg/r 'I' wire.
The voltmeter wouldn't fall out, but it would only be powered in start or run.

(I strongly suggested the choke relay for John because he seems apprehensive about electrons, and it would take literally nothing to implement -in his case-)

[Gary Lewis]

Yes, it is easy enough to use the LG/R wire to pull the relay in, but I'm kind of liking the idea of having the voltmeter die if the alternator dies.  That should tell you something, quickly.

And yes, I understand that you and I don't think the same, nor do either of us tend to think like many others.  But if we can get it down to two options then I can create those schematics.  And these are now the two options I'm thinking of:

Monitor Cab Voltage:

Monitoring Battery Voltage: I'm now seeing two options, one for 351HO's and one for all others.
 But I'm now thinking they'll essentially be the same - a relay pulled in my the stator output.  That makes things easier.

As said on the tab for this, I'd really like to have someone tell us what the differences are between battery and in-cab voltages in various scenarios.  This might help people make a decision of which approach to take.  I think the best way to do that is connect a DVM's positive lead to the battery and the negative lead to the LG/R wire at the alternator.  It really wouldn't matter too much if the truck has a 1G, 2G, or 3G alternator.

I would do it but I have taken a lot of the load off the cab with the headlight and blower motor relays.  So it would be best if someone that hasn't done those upgrades would check.  Please?

[ArdWrknTrk]

I have no shunt and all the relays up front powered directly off the Megafuse, so I can't help there.

I'm sure it is down to how oxidized the connectors are, or if any feed wires have ' The Black Death' beneath their insulation.

Reading voltage doesn't really say anything about how much current can get to the cab, only that the potential is there.
That's why we do voltage drop tests and not just check for power at something like a starter.

But we need participation.
The few of us here are not really representative of the intended audience for a tutorial.