Wiring in a larger alternator

[Kalums]

Originally Posted by Rich69shortfleet

A 10si is a one wire alternator with an internal regulator.

Well apparently I have 2 voltage regulators, but this one is set up as a 3 wire and not a 1 wire + ground... Hhhmmmm... I've also done the AC/DC (great band) test this morning and.... *ding, ding ding* we have a winner!!! It is producing AC voltage and DC voltage...so a new Alternator should fix my problem in the end... I'm going to see later if Napa is open and Just nab a standard/ New 60(ish) amp, 10si. We will see if that fixes the issue. Again thank all of you for the help.

Follow up... I just learned the difference between a 10si and a 10dn...i have a 10dn with a 3 wire hook up... So there is that. Doesn't change the fact it is putting out AC and DC voltage indicating a bad diode(s).

Learned more... My alternator has connections on the top (10si) and not the back (10dn) so further digging is needed on my part to see of someone else did or half did a conversation *shrugs*

[Orange Crate]

There are a couple of really easy checks you can do, called out in the factory service manual (available free on this forum) One is using the grounding tab provided in the back of the 10-SI to eliminate the voltage regulator after you have your test meter hooked up correctly. The diode check is called out in the manual with nice pretty little pictures too. It shows you exactly where to put the leads of the meter.

[Kalums]

Originally Posted by Orange Crate

There are a couple of really easy checks you can do, called out in the factory service manual (available free on this forum) One is using the grounding tab provided in the back of the 10-SI to eliminate the voltage regulator after you have your test meter hooked up correctly. The diode check is called out in the manual with nice pretty little pictures too. It shows you exactly where to put the leads of the meter.

Sweet, thank you. Found it! I will do my voltage (etc) checks again.

[Rich69shortfleet]

Originally Posted by Kalums

Learned more... My alternator has connections on the top (10si) and not the back (10dn) so further digging is needed on my part to see of someone else did or half did a conversation *shrugs*

Some aftermarket 10dn alternators have the plug on top instead of the back such as those made by Tuff Stuff. The question is, does it use a plug that has prongs like "| |" or "- -" The vertical ones are 10dn, the horizontal ones are 10si.

[Kalums]

Originally Posted by Rich69shortfleet

Some aftermarket 10dn alternators have the plug on top instead of the back such as those made by Tuff Stuff. The question is, does it use a plug that has prongs like "| |" or "- -" The vertical ones are 10dn, the horizontal ones are 10si.

It looks older, but they are vertical (10dn). So after testing per the service manual... I'm still getting an output of AC and DC voltage up to the regulator on the radiator support... But testing the "output" from the regulator to the rest truck is DC... BUT there is a significant voltage and amperage drop from the regulator at idle. It picks up to normal when truck is revved to 1200+ rpm on the engine... *shrugs* at this point I'm tempted to replace the alternator with a 10si or 12si and do the conversion/new wiring. I think that will benefit me most in the long run.

[Kalums]

So... Found something else interesting while poking around in/with the wires from my alternator to the battery is "solid" (think house wire/ Romex) not sure if that has anything to do with anything... But this just keeps getting stranger as I go along.

[dmjlambert]

Now we've got to see pictures...

[RichardJ]

>>I'm still getting an output of AC and DC voltage up to the regulator<<

How much AC are you actually getting ?
Unless you actually know what is going on, don't over think this AC idea.

The first image shows the 3-phase voltage as produced in the stator windings. The diodes chop off the Negative side and you end up with a 12 volt ripple as displayed in (A) in the second image. The wire resistance and the battery itself will filter and smooth out that ripple and your meter will see a 12 volt DC voltage.

Another thing to consider is the relay voltage regulation provided by the mechanical voltage regulator. The relay contacts in the upper-right side of the relay image can only supply the Field windings with 0 volts or 12 volts. The upper contact is Ground and the lower contact is 12 V. The center contact is rapidly fluctuation up and down, constantly turning the Field winding ON/OFF. This could actually be seen as a AC signal, but at a much higher frequency than the 3-phase signal.

Don't expect the 10DN output to be ripple free. The battery doesn't care, neither should you.

[Kalums]

Originally Posted by dmjlambert

Now we've got to see pictures...

Wish granted, the "coil" is what I pulled out of the truck... It went from the driver's side of the engine to the fender well and around the front over the radiator and then there was some coiled up under/behind the battery tray (or what is left of it). The second is outside next to the truck, I bent the tip back out/around, still has dielectric grease on it... Lighting in my garage is terrible. P sry for the garbage pictures.

[dmjlambert]

Interesting. I don't know what kind of wire that is. The insulation looks kind of too thick for romex.

[Kalums]

Originally Posted by RichardJ

>>I'm still getting an output of AC and DC voltage up to the regulator<<

How much AC are you actually getting ?
Unless you actually know what is going on, don't over think this AC idea.

The first image shows the 3-phase voltage as produced in the stator windings. The diodes chop off the Negative side and you end up with a 12 volt ripple as displayed in (A) in the second image. The wire resistance and the battery itself will filter and smooth out that ripple and your meter will see a 12 volt DC voltage.

Another thing to consider is the relay voltage regulation provided by the mechanical voltage regulator. The relay contacts in the upper-right side of the relay image can only supply the Field windings with 0 volts or 12 volts. The upper contact is Ground and the lower contact is 12 V. The center contact is rapidly fluctuation up and down, constantly turning the Field winding ON/OFF. This could actually be seen as a AC signal, but at a much higher frequency than the 3-phase signal.

Don't expect the 10DN output to be ripple free. The battery doesn't care, neither should you.

I learned something new today, I didn't realize/know any of that... My AC voltage fluctuates the most widely with engine rpms however there was a 2-5 volt and 0.5 amp (generally) fluctuation at idle... Again I think I'm just going to convert to a 12si and rewire... I'm already partially there ripping up/out some of the harness...

[Kalums]

Originally Posted by dmjlambert

Interesting. I don't know what kind of wire that is. The insulation looks kind of too thick for romex.

It says "drct bry 12" on it.... So I'm thinking it is direct bury 12ga THHN. *shrugs* IDK I'm not any type of electrician. (well maybe "shade tree" *laughs*)

[57taskforce]

I swapped a 10SI into my K20 close to 10 years ago and never looked back. I had a couple new external regulators that crapped out on me in short order so I upgraded. I’ve never had a problem with charging or anything like that, but electrically my truck is mostly stock. The wiring changes to go from a DN to a 10/12SI are really really small and simple. I’d bet someone hooked up the plug at the alternator backward at some point or another on yours, if that happens it will cause the alternator to go to full output and burn that wire over the radiator up. I’ve seen it a few times on these trucks.

[Kalums]

Originally Posted by 57taskforce

I swapped a 10SI into my K20 close to 10 years ago and never looked back. I had a couple new external regulators that crapped out on me in short order so I upgraded. I’ve never had a problem with charging or anything like that, but electrically my truck is mostly stock. The wiring changes to go from a DN to a 10/12SI are really really small and simple. I’d bet someone hooked up the plug at the alternator backward at some point or another on yours, if that happens it will cause the alternator to go to full output and burn that wire over the radiator up. I’ve seen it a few times on these trucks.

Not gonna lie I've given up on this endeavor I ordered a 12si (94 amp) and "conversion kit" and I'm currently wrapping my 6-8-10ga wires together with wireloom and cloth(factory style) electrical tape, to replace the wiring going across the radiator support.

[byrdman]

How'd it turn out?

[PbFut]

Something to keep in mind. The factory battery meter looks at voltage at the alternator and the fuse link block. Changing length or gauge of wire between the two will affect the sensitivity of the guage. Adding load at the fuse link block will affect accuracy as the added load at the block mimics a charging battery. You appear to be doing things correct by modifying the wire from to the main splice in the harness to the alternator. Just be aware that that main wire from splice to fuse link block is not as simple as it appears relative to the battery meter functionality.

[Kalums]

Originally Posted by byrdman

How'd it turn out?

Nothing yet, I was sent the wrong alternator... Still waiting.

[Kalums]

Originally Posted by PbFut

Something to keep in mind. The factory battery meter looks at voltage at the alternator and the fuse link block. Changing length or gauge of wire between the two will affect the sensitivity of the guage. Adding load at the fuse link block will affect accuracy as the added load at the block mimics a charging battery. You appear to be doing things correct by modifying the wire from to the main splice in the harness to the alternator. Just be aware that that main wire from splice to fuse link block is not as simple as it appears relative to the battery meter functionality.

Does anyone know the correct "lengths"? My harness is/was all sorts of hacked up and the lengths I currently have set up are from what I already had. Also should I change from the anmeter to a volt meter?

[PbFut]

Some say go to volt meter. I like the battery meter as it let's me know instantly if I am discharging. A volt meter with lead correctly placed on the harness is also useful in a different way. I am sorry I do not recall the length. I would guess guage is more critical as it will affect resistance more than a added or shortened foot of wire. Less resistance dulls the gauge reaction but that can be useful if you have super high loads (pumps, fans and amps) on the main splice that could pin the guage if alternator is not spinning. It could also overheat that jump from main splice to fuse link block. The same critically gauged and length wire we are talking about.
My solution was to up the guage size. It dulls my meter but I do not pin the gauge if the fans were running and motor not.

[Rick Bollinger]

I had read on here that all the current going to the headlights go through the switch. Another good test is check the voltage at the headlight sockets. That between dirty connections and lots of wire voltage can drop to below 11 volts at the lights. I added a relay headlight kit and it made a huge difference. Plus it takes a big load off of the switch and original harness especially if running halogen lights.