Scool Me In Wiring (1 Viewer)

[RWBeringer4x4]

It's pretty easy.
Take off the WL (White/Light Blue stripe) wire from the +B stud on the alternator. Isolate it.
Run a new wire/cable with a fusible link from the +B stud on the alternator to the battery.
This way the Ammeter only shows the current draw on the OEM wiring harness and not the charge current.

Add a new fuse block to the + battery stud and go from there for your fog lights etc.
Install a Volt meter or maybe the new alternator comes with a charge light.

Rudi

Ok @bj40green -

So let's see if I've learned anything here. Based on the schematic for a standard GM 3-wire alternator (10SI or 12SI), below:

Then I should be wiring up the cruiser something like this - in order to isolate the Ammeter from the alternator?

Am I anywhere close? Go easy on the drawing...it took my whole lunch break

 

[bj40green]

Almost good
Except that the WL goes to the ignition switch.

Just looking at the +B from the alternator it's going to be like this.
Note: the splice in this diagram is actually behind the gauge cluster where it splits up into the wire to the ign switch and and the wire to the Ammeter..

Rudi

 

[RWBeringer4x4]

Almost good
Except that the WL goes to the ignition switch.

Just looking at the +B from the alternator it's going to be like this.
Note: the splice in this diagram is actually behind the gauge cluster where it splits up into the wire to the ign switch and and the wire to the Ammeter..

Rudi

I'm not sure I understand the splice point that you are referring to - I think the confusion comes from my lack of understanding of what is going on behind the dash. At some point the "WL" (White/Blue) wire SPLITS into two WL wires - one to the ignition switch, and one to the Ammeter?

So, one last effort to figure out what I have going on here. I THINK, currently, it is (or should be) something like this -

And in order to get a GM 3-wire alternator to work, and isolate the AMP meter from the increased current, I need to do this:

Really - the only thing that confuses is me - where do I wire in the "Field" wire. On the diagram, it looks like it should hook right up to "WL" but "WL," at least where my alternator is currently hooked up to it, is something like a 10ga wire. Way too thick for the field wire to splice to. If there is a thinner "WL" that splits off to the igniton switch behind the dash, it would make more sense to splice in there. HOWEVER, when all is said and done, that would leave the big "WL" 10ga wire currently in the engine bay totally disconnected...

This is the WL I'm referring to in the engine bay, currently butt-spliced to the alternator:

Could I just unplug the alternator from that WL wire, and run the field wire straight into it with a resistor and call it done, or is that WL line not "switched" with the ignition?

I feel like that doesn't really adequately complete the main harness circuit, you would need to do something like this:

Sorry - it's like...4 friggin wires and it is making me feel like a complete idiot!

 

[bj40green]

1st picture is what you have now. Fine, forget it.
2nd picture is correct !!!! keep it! I don't like the word Field. It should be called: L (LAMP) !! BTW, this is also the on/off wire for activating the alternator.
3rd picture, yes that White/Blue wire must be cut, taped and bind up and stays where it is. Maybe for the future if you you want to go back to OEM.
4th picture, delete it. same error as before, the WL goes back to the battery and that means that the Ammeter is shortened and will do NOTHING, and the resistor/warning light is hooked up to the wrong side of the switch. Alternator is forever on and will drain your battery.

Happy New Year

I'm off now, till next year.

Rudi

 

[RWBeringer4x4]

Rudi - this thread was titled "school me in wiring" and you most certainly have! Thank you for your time and words of wisdom.

So I will tape off that heavy gauge WL wire, go find my ignition switch, splice in the "field/light" wire to the thinner "WL wire" or some other switched 12V source. I'll make sure there's a resistor or a light (or both in parallel) on that line - and everything else (seems) straightforward.

Happy new year! Thanks again!

 

[Solace in Solitude]

Great work Rick!! ...and always great work Rudi!! He schools everyone he meets!!

Happy New Year everyone!!

 

[bj40green]

This is really the last one for this year.....
How about using the "old" wire that goes to no. 4 on the old regulator?

Feliz año nuevo, happy new year, gelukkig nieuwjaar,

Rudi

 

[Solace in Solitude]

Feliz año nuevo, happy new year, gelukkig nieuwjaar,

Rudi

Gelukkige oude jaar avond, Rudi!!

 

[bj40green]

Jij en je

ook Danny,

Time for a drink or two

and some music

(my other hobby)

Rudi

 

[RWBeringer4x4]

This is really the last one for this year.....
How about using the "old" wire that goes to no. 4 on the old regulator?

Feliz año nuevo, happy new year, gelukkig nieuwjaar,

Rudi

Hey Rudi -

Hope you had a wonderful New Year celebration. Mine was a little TOO MUCH fun - nursing a pretty serious hangover today!

To answer your last question about the existing brown wire - I probably could (and may very well do just that). It is currently routed to the wrong side of the truck, but that is pretty easily remedied by yanking it back through the dash and out a different firewall grommet.

Before I do anything, I really need to confirm that it does, indeed, connect to the ignition switch. I've traced it up under the dash, but I haven't been able to find the other splice point to determine what it is wired to. Since the regulator isn't currently regulating, I have no way of knowing whether or not it is properly hooked up.

In addition, I would need to figure out whether or not it is a "resistance wire" found in many GM alternator applications. If the wire itself provides resistance, I would not need to add the diode/resistor/idiot light to the circuit. However, that banks on the resistance wire being the correct length (unmodified) to provide the correct resistance. Quite a few variables there - may be best to just run a new wire with a resistor in series...

Either way, I'll probably need to get up in the dash wiring and figure out where the brown wire goes. Of course, it's a nightmare in there as well.

 

[RWBeringer4x4]

It's pretty easy.
Take off the WL (White/Light Blue stripe) wire from the +B stud on the alternator. Isolate it.
Run a new wire/cable with a fusible link from the +B stud on the alternator to the battery.
This way the Ammeter only shows the current draw on the OEM wiring harness and not the charge current.
Rudi

Just looking back at this, I do have one additional question: Will the ammeter still show charging current, or will it operate basically as it does now - the needle will only move "negative" if my blinkers are flashing or accessories turned on?

 

[bj40green]

Before I do anything, I really need to confirm that it does, indeed, connect to the ignition switch. I've traced it up under the dash, but I haven't been able to find the other splice point to determine what it is wired to. Since the regulator isn't currently regulating, I have no way of knowing whether or not it is properly hooked up.

Take your voltmeter and check for voltage when the key is in the on position.

Just looking back at this, I do have one additional question: Will the ammeter still show charging current, or will it operate basically as it does now - the needle will only move "negative" if my blinkers are flashing or accessories turned on?

Yep, that's what I wrote. Only showing negative. To check the charge status you've to add a voltmeter.

Rudi

 

[RWBeringer4x4]

Take your voltmeter and check for voltage when the key is in the on position.


Yep, that's what I wrote. Only showing negative. To check the charge status you've to add a voltmeter.

Rudi

Ok - thanks for clarifying!

 

[RWBeringer4x4]

Confirmed @ local auto parts store tonight - alternator is dead. Produced a max voltage of 1.25V...

So, looks like I'm going to be investing in a re-wire to an internally regulated, 3-wire setup.

 

[71FJnick]

Bummer, but at least once you get the 3 wire set up, you'll know it's done correctly.
After I did mine it took all the voodoo out of the alternator circuit and I felt way better.

 

[RWBeringer4x4]

Yeah - I was actually hoping it was something as simple as "dead alternator." If the alt has been fine, and the system still wasn't charging, I would have had a more difficult task ahead. Now it's just a matter of pulling the old wired, ditching the voltage regulator, mounting up a 10SI or 12SI model 3-wire, and isolating the ammeter from the charging circuit to prevent an overcharge/fire hazard.

I'm going to add a diode to the exciter wire and forego the "idiot light," but I should probably wire in a voltmeter. I'll have to find an elegant way to mount these extra gauges without chopping up the dash too badly...

 

[bj40green]

Something like this?

Rudi

 

[RWBeringer4x4]

Something like this?
View attachment 1012492

Rudi

Certainly more elegant than my current oil pressure gauge setup - wedged in the hole where the radio used to be.

 

[edwjmcgrath]

A cheap and simple way to add a voltmeter without chopping up your dash is one of these (or equivalent):

http://www.amazon.com/gp/product/B0..._m=ATVPDKIKX0DER&pf_rd_r=1F5SNN0KYNBWRX8406ZG

 

[RWBeringer4x4]

Well, another setback - ordered a bunch of 10 gauge wire to run a new cable from the alternator to the battery, with some 12 gauge fusible link wire. Come to find out, due to the length of the run, chances are I'll need something closer to 6 gauge...which means I'll also need a bigger fusible link, to run anything much higher than the standard output of 63 amps. Do I need 63 amps right now, probably not? Does it make sense to upgrade to a beefier charging system to sustain future accessories...probably... It seems like even running the next step up in stock alternators, ay 78 amps, has the potential to burn 10 gauge... Spent all night looking for 6 gauge wire at a reasonable price, but not having too much luck so far. Search will continue in the morning...