2006 GMC Yukon SLT 5.3 flex CHARGING SYSTEM

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Douglas Friedberg

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While I have worked on a lot of vehicle charging systems from 1949 thur 1990,s systems yet another has surfaced to play with. Generators to alternator external regulators to internal regulators, here’s what I learned on this system that I want to share.
My 2006 is a two wire plug alt unit which does have a internal regulator but not fully functional on its own system. The two pin plug is connected to the vehicles control system or on board computer network. Two modules enclosed one the PCM and second a generator control module. It’s all done to save fuel by controlling the alternators load output. It relys on the battery to do the work where in the past the gen or alternator handled the load and floated the battery keeping it fully charged. During braking the alternator flares to 15.1 volts to add engine braking and charging the battery during normal driving there are three more voltage settings depending on what vehicles computer system see as loads being used. Lights ac blower speeds etc. The alternator will work with the 2 prong plug unplugged but only at 13.2 volts. When driving it’s about 13.5. When battery is full it shuts off alternator. They call this a smart system *****.
All in the names of EPA gas milage mandates. Ford uses the slip clutch on its alternators from what to what I do not know.
But brings me to two thoughts. Alternator belt wear promoted and earlier retirement of your battery.
I acquired this and some of this info from a resonsable rebuilder and manufacture.
Looking at higher amperage alternators and designs. Most alternators are as you know really AC generators with 6 diodes to rectifi the ac into dc
Yes same AC as your household electric but diff cycles. Household is 60 cycles it goes on and off at 60 times a second so fast your eyes can’t see this. Point of interest.
DC is always on at its voltage. Hence AC is alternating current and DC direct Current.
They make 12 phases alternators now as standard alt are 6 phases. Which is called the stator windings (outer coil of wire) what you see inside. The field coil or called rotor produces the magnetic field much like a magnet to make electricity. Point being is the brushes that make the connections slip rings have gotton much smaller wear out unusable so rebuilding at home next to impossible now. Complete system must now be replaced not just brushes.
And alternator size is built by its field strength and stators size and of course the size of the diodes. The big high amperage alternators use 12 phases and 12 diodes monsters. But a good 6 phase standard is all we normally need. Alternators are rated at A. Amperage output but it’s a numbers game be careful. As it also needs at what volts 15,14,12 or 9 volts in the past they used 9 volts to make the amps look good and gets less amps at 14 volts like the watts and music sound systems game people buy numbers not quality. Be a smart shopper. Also it’s about at what rpm. Mostly Eng rpm not alternator rpm there’s a big diff. Alternators have a very small pulley for a reason to triple and more it’s speed so it works better at lower rpms of the engine. About 5-6 times faster then engine RPMs. Generators are monsters producing all DC but less effective at low engine rpms. Alternators are more effective at low engine speeds this why there used more today.
Project you can build a nasty go kart using a starter motor and a few batteries.

So todays computers do most of the controlling of todays alternators making trouble shooting alittle harder and more wear and tear on the battery and Pullies and belts.
I am sure there’s more to this story and would help to add to this please do.
Douglas
 

B-train

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Very informative. I know all the newer stuff is controlled on/off for EPA ratings. But, I didn't realize how in depth it really went. Very nice write up!
 

RAMurphy

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Learned a bit here on this post on how complicated the newer vehicles are getting. I've said many times that my wife's 2020 vehicle is smarter than me. Great write up.
 

Billy Ray

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While I have worked on a lot of vehicle charging systems from 1949 thur 1990,s systems yet another has surfaced to play with. Generators to alternator external regulators to internal regulators, here’s what I learned on this system that I want to share.
My 2006 is a two wire plug alt unit which does have a internal regulator but not fully functional on its own system. The two pin plug is connected to the vehicles control system or on board computer network. Two modules enclosed one the PCM and second a generator control module. It’s all done to save fuel by controlling the alternators load output. It relys on the battery to do the work where in the past the gen or alternator handled the load and floated the battery keeping it fully charged. During braking the alternator flares to 15.1 volts to add engine braking and charging the battery during normal driving there are three more voltage settings depending on what vehicles computer system see as loads being used. Lights ac blower speeds etc. The alternator will work with the 2 prong plug unplugged but only at 13.2 volts. When driving it’s about 13.5. When battery is full it shuts off alternator. They call this a smart system *****.
All in the names of EPA gas milage mandates. Ford uses the slip clutch on its alternators from what to what I do not know.
But brings me to two thoughts. Alternator belt wear promoted and earlier retirement of your battery.
I acquired this and some of this info from a resonsable rebuilder and manufacture.
Looking at higher amperage alternators and designs. Most alternators are as you know really AC generators with 6 diodes to rectifi the ac into dc
Yes same AC as your household electric but diff cycles. Household is 60 cycles it goes on and off at 60 times a second so fast your eyes can’t see this. Point of interest.
DC is always on at its voltage. Hence AC is alternating current and DC direct Current.
They make 12 phases alternators now as standard alt are 6 phases. Which is called the stator windings (outer coil of wire) what you see inside. The field coil or called rotor produces the magnetic field much like a magnet to make electricity. Point being is the brushes that make the connections slip rings have gotton much smaller wear out unusable so rebuilding at home next to impossible now. Complete system must now be replaced not just brushes.
And alternator size is built by its field strength and stators size and of course the size of the diodes. The big high amperage alternators use 12 phases and 12 diodes monsters. But a good 6 phase standard is all we normally need. Alternators are rated at A. Amperage output but it’s a numbers game be careful. As it also needs at what volts 15,14,12 or 9 volts in the past they used 9 volts to make the amps look good and gets less amps at 14 volts like the watts and music sound systems game people buy numbers not quality. Be a smart shopper. Also it’s about at what rpm. Mostly Eng rpm not alternator rpm there’s a big diff. Alternators have a very small pulley for a reason to triple and more it’s speed so it works better at lower rpms of the engine. About 5-6 times faster then engine RPMs. Generators are monsters producing all DC but less effective at low engine rpms. Alternators are more effective at low engine speeds this why there used more today.
Project you can build a nasty go kart using a starter motor and a few batteries.

So todays computers do most of the controlling of todays alternators making trouble shooting alittle harder and more wear and tear on the battery and Pullies and belts.
I am sure there’s more to this story and would help to add to this please do.
Douglas
Good info. A few months ago when I was on vacation I had an issue with the remote, the doors locking and unlocking continually while driving and of course checking charging from gage which was below 14volts. Of course worrying I would breakdown on the road. I took the battery out of the remote but still worried watching Gages. Made it home, checked every thing and just figured the alternated works like in your post. I never could find any info.,but now feel better after reading your post,thanks for sharing
 

Donal

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While I have worked on a lot of vehicle charging systems from 1949 thur 1990,s systems yet another has surfaced to play with. Generators to alternator external regulators to internal regulators, here’s what I learned on this system that I want to share.
My 2006 is a two wire plug alt unit which does have a internal regulator but not fully functional on its own system. The two pin plug is connected to the vehicles control system or on board computer network. Two modules enclosed one the PCM and second a generator control module. It’s all done to save fuel by controlling the alternators load output. It relys on the battery to do the work where in the past the gen or alternator handled the load and floated the battery keeping it fully charged. During braking the alternator flares to 15.1 volts to add engine braking and charging the battery during normal driving there are three more voltage settings depending on what vehicles computer system see as loads being used. Lights ac blower speeds etc. The alternator will work with the 2 prong plug unplugged but only at 13.2 volts. When driving it’s about 13.5. When battery is full it shuts off alternator. They call this a smart system *****.
ufacture.
Looking at higher amperage alternators and designs. Most alternators are as you know really AC generators with 6 diodes to rectifi the ac into dc
Yes same AC as your household electric but diff cycles. Household is 60 cycles it goes on and off at 60 times a second so fast your eyes can’t see this. Point of interest.
All in the names of EPA gas milage mandates. Ford uses the slip clutch on its alternators from what to what I do not know.

But brings me to two thoughts. Alternator belt wear promoted and earlier retirement of your battery.

I acquired this and some of this info from a resonsable rebuilder and man
DC is always on at its voltage. Hence AC is alternating current and DC direct Current.
They make 12 phases alternators now as standard alt are 6 phases. Which is called the stator windings (outer coil of wire) what you see inside. The field coil or called rotor produces the magnetic field much like a magnet to make electricity. Point being is the brushes that make the connections slip rings have gotton much smaller wear out unusable so rebuilding at home next to impossible now. Complete system must now be replaced not just brushes.
And alternator size is built by its field strength and stators size and of course the size of the diodes. The big high amperage alternators use 12 phases and 12 diodes monsters. But a good 6 phase standard is all we normally need. Alternators are rated at A. Amperage output but it’s a numbers game be careful. As it also needs at what volts 15,14,12 or 9 volts in the past they used 9 volts to make the amps look good and gets less amps at 14 volts like the watts and music sound systems game people buy numbers not quality. Be a smart shopper. Also it’s about at what rpm. Mostly Eng rpm not alternator rpm there’s a big diff. Alternators have a very small pulley for a reason to triple and more it’s speed so it works better at lower rpms of the engine. About 5-6 times faster then engine RPMs. Generators are monsters producing all DC but less effective at low engine rpms. Alternators are more effective at low engine speeds this why there used more today.
Project you can build a nasty go kart using a starter motor and a few batteries.

So todays computers do most of the controlling of todays alternators making trouble shooting alittle harder and more wear and tear on the battery and Pullies and belts.
I am sure there’s more to this story and would help to add to this please do.
Douglas
 

Donal

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A battery with a weak cell, poor connections, high resistance, etc can be hidden by the new system. The battery then is dead with warning. I am replacing battery every three years in the vehicles that I have or maintain.
 

Horsepowerguru

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On some of the models with the 160amp alternator (2pin) there is a system called RVC or regulated voltage control and if the PCM decides that voltage is too much or too little or that more or less can be used to save gas then it is able to control output voltage anywhere from 10.5v-15v as needed.
 
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Douglas Friedberg

Douglas Friedberg

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Lamps are rated at 12.6 or so and then you have a 15.0 vdc spiking system. Not good for lamp life. Phillips lamps burned out in 30 days headlamps. Not happy about that esp when the dumb heads Engineers and accounts make it near impossible to change a lamp in the headlight systems now. Great for the assy line not for maintenance.
 

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