Used 2000 Ford Mustang Alternator Scenario...

Discussion in 'Automotive Electronics' started by RandyFL, May 1, 2016.

  1. RandyFL

    Thread Starter Member

    Aug 28, 2014
    116
    0
    I have a 2000 Ford Mustang 3.8 which I thought was having a bearing noise issue... I thought the noise was coming from the alternator and bought a new one from the local auto parts store in my area... you purchase a new or rebuilt alternator and you bring in the old one... I kept the old one in my garage and put it on a shelf and drove around with the new one ( which didn't solve the bearing noise - but at this point who cares ). 6 months ago whilest going thru my garage I ran across this alternator just sitting there whenst a idea came to me to see how these generators actually work... I knew that their actual function was to recharge the batteries and run the creature comforts in the car interior...I have a 12 volt DC motor in place with a small lawn mower battery to run it... 1. I need to know exactly how to place the 3 prong pigtail socket into a circuit... here is the circuit wire diagram to begin with: https://www.google.com/search?q=200...X&ved=0ahUKEwjo8oKIu7jMAhVLmx4KHR9dA6EQ7AkIMA
    2. I bought two new 3 prong pigtail sockets from the local auto parts store... one of the prongs actually goes back to the alternator... but where ( I need to be specific as to buy a new alternator ( they are quite expensive - even for do it yourselfers )).
    3. Do I need to have a separate battery for the field ? or how does that work?
    4. I know that the alternator puts out 3 phases AC - with heavy duty silicon diodes that converts to DC that charges the battery but can you induce the alternator to run at higher speeds... I have a large pulley on the 12 volt DC motor that will run the alternator at higher speeds but can the alternator be induced to put out more?
    If you need more info I will include...
    Thanx in advance
     
  2. bwilliams60

    Active Member

    Nov 18, 2012
    722
    88
    I am assuming this in an internal regulator type alternator. Ford dubbed it the 2G (2nd generation) alternator and was quite popular on their line of products. The unit was quite famous for catching fire because of poor connection on the three prong connector.
    As for the hookup, the two large black/orange wires are the main battery output and go directly back to the battery positive post. Thecsmall white/black wire is a stator tap wire and goes to the same colored wire in the second connector. The yellow and white wire is a sense wire and is there to tell the regulator what the charge rate is so it can adjust accordingly. It also goes directly to battery positive. The light green and red wire goes through a bulb (194 will do) and back to battery positive to indicate when it is charging. You can put a switch in series with this if you like to simulate the ignition. The case of the unit serves as ground.
    To drive this unit, you will need a fairly good sized motor to do it. Once this unit starts up, it becomes a large magnet and takes some horsepower to keep it moving.
    As for how it works, a quick Google search will do but if you need to know more, I can fill in the blanks.
     
  3. Tonyr1084

    Active Member

    Sep 24, 2015
    535
    86
    Your link brings me to over 300 images of alternators or alternator parts; so I don't know which scenario you have.

    The alternator has three phases, all of which produce electrical energy - one after the other after the other. At all times at least two phases are producing energy, so that energy can be used in part to excite the armature (rotor) windings (the part that spins). But simply spinning an alternator isn't going to produce any power. It first needs to be excited by a voltage from a battery. Even a low voltage can excite enough energy to bring the alternator up to full potential.

    Alternators are internally regulated so that they produce a steady (but not pure) DC voltage. Diodes rectify the current so that their combined waveforms overlap leaving very little DC ripple. Still, it's there.

    The alternator should have a heavy screw terminal. That is the DC output that goes to the battery and auto electrics. The pigtail connector supplies power (and probably ground). I'm trying to remember the Toyota alternator I mounted on a small gasoline engine and battery frame, it's pigtail had three wires too. Somewhere in my archives I have a schematic of how I built my rig. I'll search for it and when (if) I find it I'll edit this post to include the schematic. Hopefully it will yield some useful information for you.

    OK, in the attached drawing there are three wires on this Denso (for Toyota) alternator. Likely yours is going to be similar. There is an "Ignition" lead. It needs to be powered for the alternator to produce energy. It's akin to the key switch on the dash. When you start the car the "ignition" wire becomes energized, thus, turning on the alternator. Another wire is the "Sense" wire. I take it to be the wire that is connected to the battery. It provides reference for the internal regulator to decide how much energy the field winding needs to produce sufficient charging current for the battery. The last wire is the "L" wire - I believe it's an output wire to signal the dash to light the battery light when the alternator is not producing enough power.

    As to the exact configuration of your alternator - I can't say for sure. On my rig I have the "L" wire simply taped off and not connected to anything. I'll search around and see if I can find more drawings - and I think I have a video too. Noisy, but it's there.

    Found one more drawing but it won't post. Possibly too big.

    AND it seems like BWilliams60 knows more about this alternator than I do. So since the best I can do is be general - I'll sit back and see what develops.

    Good luck.
     
    Last edited: May 1, 2016
  4. bwilliams60

    Active Member

    Nov 18, 2012
    722
    88
    This particular unit does not have an output post and the case in most automotive alternators serves as ground. Class 8 trucks can use case ground or an external ground. The output on this unit comes directly out of the rectifier assembly in the form of two large black/orange wires. This connector should always be replaced when replacing the alternator. See above.
     
  5. Kev0511

    Active Member

    Jul 20, 2004
    39
    1
    I would believe you'll need a battery to excite the field via the "I" terminal, and chances are once it gets going it'll continue producing power until the RPMs get too low that it won't be able to produce enough power to keep the field excited?

    Basicaly what bwilliams60 has said, but being you should have a 3G alternator and not a 2G (hook up is basically the same except for the output), one lead (I) goes to an indicator and then to switched 12V, Another goes (S) that goes back into the alternator for the stator, and the last goes to the battery (A) which is used as a output voltage sense. then you have the large single (5/16" stud?) that's the output.

    Click here to read more

    Also you may need a bit more than a small 12V DC motor to run it by the way, Also remember the alternator itself may need about 2500+ RPMs to start producing power (usually they are ran at a 2.5-3.0 : 1 of the crank)
     
    Last edited: May 1, 2016
  6. bwilliams60

    Active Member

    Nov 18, 2012
    722
    88
    Good catch on the 3G. I used to be an alternator rebuilder and built a lot of both of these. I forgot the 3G came out in the late 90's.
     
  7. RandyFL

    Thread Starter Member

    Aug 28, 2014
    116
    0
    Here is a picture of the 12 Volt DC motor... its about 60 or 70 amps I think. And yes it has a internal regulator attached to it... the pulley size is either 7 or 10 to 1. I bought 2 pigtail/sockets from a local auto parts store but they didn't have the socket that doubles back into the alternator and neither did the Local Ford dealer...I have a wiring diagram from the Haynes paperback of the 2000 Ford Mustang...

    I just read the " read more " section ^ above... I wish I had known about those specific issues before I bought my replacement alternator ( hindsight is always 20/20 )... I may have another alternator to experiment with down the line when I switch out for a higher amperage alternator... but for now I want to see how this motor and alternator scenario works out...
    I was thinking that a second battery for the field so I could adjust the output ( I don't know if that's completely right ? that's why I wanted to bring this idea to the forum...

    thanx in advance
     
    Last edited: May 2, 2016
  8. Tonyr1084

    Active Member

    Sep 24, 2015
    535
    86
    Trying to upload another drawing; don't know why it doesn't want to. I think you'll like this one though.

    https://www.dropbox.com/s/vg2xesa8wjozp8a/Toyota Alternator Hookup copy.bmp?dl=0

    In this drawing I have the option for a meter. Not sure even now if it should be an amp meter or a volt meter, but somewhere when I researched this project it suggested the "L" wire could be hooked up to a volt meter. If in fact it's supposed to be hooked to the battery indicator light then perhaps it can double as an amp meter but I don't know for sure. Nevertheless, I built this. I'll try to find my video too.

    Hope this helps.

    ˚J˚
    ˘
     
  9. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,347
    Hello Tony,

    The image is in a not supported file format (.bmp).
    I have converted it to .png:

    tony_Toyota_alternator_hookup.png

    Bertus
     
  10. Tonyr1084

    Active Member

    Sep 24, 2015
    535
    86
    Thanks Bertus.

    I was hoping to find a video of my rig operating. I've come close with some pictures of my rig but they don't offer anything useful. Nevertheless, here's a single shot of my rig.

    The switch is an ON-OFF-ON DPDT switch. In the DOWN position the engine's ignition is shorted to ground (kill switch). In the OFF position the engine can be started but the alternator puts no load on it. In the UP position the battery activates the "Ignition" line of the alternator and it begins to produce power.

    The gasoline engine is a small roto-tiller 4 cycle engine. It has some pretty high RPM's but I don't know exactly what they are. It's direct drive (via a centrifugal clutch) - so the alternator RPM's are 1 to 1. Even then it still produced a measurable charge. I didn't have a chance to check the amperage so I can't attest to how well it functions, all I CAN attest is that it functions.

    The hope is to one day attach an inverter to power "Something".
     
    Last edited: May 2, 2016
  11. Kev0511

    Active Member

    Jul 20, 2004
    39
    1
    RandyFL

    I do believe you only need a female 1/4 quick connect for the one leads that goes back to the alternators stator. Yes the OEM connector is nice, since it locks the terminal on, but it's really needed for operation.

    With the 130amp 3G i think you can get @20-30 amps at about 2500rpm (alternator speed, IE engine idle in car) and it just goes up as the RPMS go up, but remember there is a limit to what the alternator itself can do. @12,000 rpm going by OEM rev limiters?? Voltage should pretty much say even through out the power producing RPM range, maybe even drop as the demand drops?
     
  12. Kev0511

    Active Member

    Jul 20, 2004
    39
    1
    When i was younger, i used an alternator driven by a 1/3hp AC motor to charge a battery. yes not the most efficient way of doing it, but it got me understanding the mechanics and wiring and general workings of a Charging system (Early 70's Ford)
     
  13. RandyFL

    Thread Starter Member

    Aug 28, 2014
    116
    0
    Let me go back to the beg...
    If the alternator has to be running at a certain speed to produce energy... how fast?
    I have a 7" inch pulley ... what's the ratio that keeps the alternator producing?

    R
     
    Last edited: May 21, 2016
  14. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,800
    1,104
    See post #5.
    :confused: You'll have to explain that.
     
  15. Tonyr1084

    Active Member

    Sep 24, 2015
    535
    86
    To get the ratio you'll need to work backwards. Start with the desired RPM of the alternator. Lets assume you want 5000 RPM. (and keep in mind I am making many assumptions based purely on the numbers)(this doesn't mean that 5000 RPM is what you want - for that you're best off talking with someone who KNOWS the ideal speed - I don't). OK, so assume you want 5K RPM. How many RPM does your motor expect to spin at on 12 volts DC? (Actual speed may depend on whether you're powering it with a car battery - potentially 13.5 volts). Lets assume your motor spins at 3900 RPM. Your ratio would be 3900 to 5000. (OR 39 to 50). Off hand I would guess that your pulley diameter on the alternator is around 2 1/2 inches (2.5" assumed). Divide 3900 (assumed motor RPM) by 5000 (assumed target alternator RPM) and you get 0.78. (3900 ÷ 5000 = 0.78) Take the reciprocal of that (1 ÷ 0.78 = 1.282) and multiply that by the alternator pulley diameter (2.5" x 1.282) for a motor pulley diameter of 3.205 inches. A ratio of 1 to 1.282. For every single rotation of the motor the alternator will rotate 1.282 times.

    Lets check the math: 3900 (motor RPM) x 1.282 = 4999.8 (alt. RPM).

    Keep in mind that the larger the motor pulley the faster the alternator will spin. HOWEVER the larger the motor pulley the more torque you place against the motor. In other words the motor will slow down with the more load you place on the alternator. The total power you'll be able to generate with the motor/alternator combination will largely depend on how much power the motor can produce. Take into account other factors such as friction and heat loss and your power output will drop.

    If the motor is capable of (as you said, 60 or 70 amps)(12 x 65 =) 780 watts then (in a perfect scenario) the alternator will be able to produce no more than 780 watts. Since we know there's going to be loses I'll guess (I said "Guess") that you're total wattage output capabilities will be around 550 watts. (780 x 0.7071) or little more than 45 amps.

    You said you're planning on running this motor with a small lawnmower battery. IF the battery itself is not capable of producing 45 amps (and you said your motor draws 60 to 70 amps) then you're building a ship out of screen door materials. It's not going to float. EVERYTHING needs to be taken into account in order for this to work. Which leads me to wonder why you want to take 12 volts to generate 12 volts. I'm sure you have your reasons though. Hopefully you can find the answers you seek.

    May the force be with you.
     
  16. Tonyr1084

    Active Member

    Sep 24, 2015
    535
    86
    Are you trying to build an "Over-Unity" machine? A battery to run a motor to run a generator to charge the battery to run the motor to run the generator to charge the battery to run the motor to run the generator to charge the battery (over and over and over)? If so then save yourself a lot of wasted time and money, this doesn't work. And YouTube is NOT your friend.
     
    shortbus likes this.
  17. RandyFL

    Thread Starter Member

    Aug 28, 2014
    116
    0
    update...
    Sorry I had every intention of bringing my laptop to continue working on this project whilest on vacation up in the Mtns. ( to ask pertinent questions about this circuit )...on the day before I left, I was finishing up on my bills and paperwork and in the maelstrom of packing and getting out of dodge I realized my laptop wasn't with me. All I had was my iPhone and iPad ( and I never leave passwords or accts on either )...

    1st... This forum ( thread or whatever you call it isn't about overunity or free energy...its my understanding... its about electronic circuits and electricity and magnetism within known Laws and fundamental basic electricity and electronics... And that is where my intent and questions are aimed at...

    2nd my intention was/is to build a circuit that ran a motor ( that part is over... I still have questions about it but that's another thread...) that runs a alternator ( bottom line = it was just sitting there...) a. how much energy does it take to run it b. how much energy does it produce c. how fast does it run to produce energy to recharge a battery ( a lead battery isn't very efficient I hear - two hrs to charge and when charged it only runs for an hour = very un efficient ) d. does a larger alternator produce ?...

    3. the third part of my experiment is to see if an alternator can be made into a motor ( but I haven't finished the 2nd part )

    Hope this answers my " intent " into this project...
     
  18. RandyFL

    Thread Starter Member

    Aug 28, 2014
    116
    0
    " If the alternator has to be running at a certain speed to produce energy... how fast? "
    And if its not running ( at what speed ) its too slow...
     
    Last edited: May 14, 2016
  19. Tonyr1084

    Active Member

    Sep 24, 2015
    535
    86
    In post #15 I said:
    Calculating pulley ratios is as easy as fractions. OK, I know, not everyone is good with fractions. Well, whatever pulley combination you use, be it a 2 1/2 inch (alt pulley) and a 7 inch (motor pulley) that would be 2.5/7 (two point five over seven) (which is an improper fraction) this equates to a 5 to 14 ratio (2.5 x 2 and 7 x 2). Because the motor has the bigger pulley the smaller pulley will turn 14 times to every 5 rotations of the motor. Knowing the RPM of the motor, you can divide that by 5 and then multiply that by 14. (or divide out 14 by 5 and you get 2.8 for a 2.8 to 1 ratio)

    Suppose your motor runs at 3900 RPM (as picked in post #15), divide that by 5 (= 780) then multiply that by 14 (= 10,920). In theory your alternator will be spinning at nearly 11,000 RPM. I'm confident that is sufficient RPM - it may be on the excessive side, but considering your typical engine can spin around 6,000 RPM and (it's my guess) the main crank pulley may be 5 inches in diameter, given the hypothetical alternator pulley size of 2 1/2 inches, that's a 2 to 1 ratio; meaning the alternator spins twice as fast as the motor. So at 6,000 RPM the alternator may see 12,000 RPM.

    If the target RPM on the alternator is 5,000 RPM, and considering the engine spins at around 750 RPM at idle (1500 alt RPM at idle) and typical highway RPM is around 2500 RPM (5000 alt RPM at highway), I'd say that if your electric motor is spinning at 1800 RPM with a 2.8 to 1 ratio your alternator will be turning at 5,040 RPM. Using the 10 inch pulley is just way overkill in my opinion. Only you know what your final goal is.

    Other things to keep in mind - your 60 to 70 amp motor (65 amp mean) at 12 volts (not 13.8 v) will have a wattage output of 780 watts (12 x 65). That's 1.046 horse power. Why convert to horsepower? Well, it's important to know what the motor CAN do. Lets call it an even 1 horse (746 watts). Your alternator is likely going to be able to push maybe 80 amps (if powered with a sufficient power source - like a car engine) (that's 960 watts) (or about 1.3 HP). That's more power than your electric motor can produce. Therefore your alternator is going to place a heavy drag on the motor, slowing it down drastically. If you try to compensate using the 10 inch pulley the alternator will only pull the motor down even more.

    In the end - in a PERFECT world - you can only get out what you can put in. If all you can put in is 750 watts of power then - in a perfect world - you can get only 750 watts. If you try to pull that much power (960 watts) out of the alternator then your motor will overheat and likely fail - possibly in a spectacular fashion.

    Like I said before - I don't know what your end goal is. If it's to learn how and why then I hope the experience and wisdom gained can be useful to you and to others to whom you may give instructions later on in life. Energy can be converted from one form to another. It can not be created, nor can it be destroyed. In the conversion from one form to another some energy is lost. Heat (friction) or drag (wind restriction) or some other parasitic losses - one thing remains constant - energy in equals energy out. And energy out must include the losses. No, it's not destroyed, it's wasted. But it still exists.
     
  20. shortbus

    AAC Fanatic!

    Sep 30, 2009
    4,013
    1,531
Loading...