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  1. #1
    FEP Super Member 69clark's Avatar
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    Default Charging issues, I think. Any help?

    Well the other night, I finally got the car on the road and went to the gas station to get gas. After I was done I went to start the car and it barely started (weak battery), it was getting late so I just put it away for the night. Next day started the car (little sluggish) pulled it out and shut it off. Then I remembered the battery seemed weak for the night before so I jumped it to see if it would crank again. Well at this time it was too dead.

    So I jump the car pull it in the garage and put a charger on it and it charged up fine and seemed to hold the charge. I got thinking that maybe the alternator wasn't charging so I put a meter on the battery, it was at about 12.4v not running. Started the car again to check it while running. No real change, if anything it was done to 12.3v running. So I assumed the alternator needed replacing.

    So today I picked up and alternator and put it in the car and checked the volts without the car running and with it running. Again, basically the same thing. So I don't know what else it might be. If I am correct do the 79's have an external voltage regulator that could be bad and if so, could this cause the problem I am having or is it something else? Also (being I am now in the house, not in the garage) where is the voltage regulator located?

    If its not the voltage regulator what else could I check? BTW, I took the car out tonight for about 1 - 1 1/2 hour drive and had the headlights on half of the that time. I checked the battery after I got back and it was about 12.2v. So it was a little lower, but if it wasn't charging wouldn't the headlights have drawn the power down even more than that?

    Thanks guys.
    Tom

    CAMMED & SLAMMED! For more build pics and updates: http://www.facebook.com/SINISBuilt


    For being "BUILT not BOUGHT" I am still broke!

  2. #2
    FEP Super Member TWR2003's Avatar
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    Default

    Thru 86 Mustangs used 1G alternator with external regulator. Im sorry you already threw an alternator at the problem - there is a simple test that can isolate a bad alternator from a bad regulator. Also any decent auto parts store should have ben able to test your alternator off your car - usually for free.

    T
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  3. #3
    FEP Super Member 69clark's Avatar
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    Default

    Well, am fine with the new alternator, it doesn't hurt to be replace and it was rather cheap. I wondered at first before I did all of this whether the voltage regulator might have been my problem, but being I work when every place is open I didn't really have the luxury of having a parts store test it for me.
    Tom

    CAMMED & SLAMMED! For more build pics and updates: http://www.facebook.com/SINISBuilt


    For being "BUILT not BOUGHT" I am still broke!

  4. #4

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    Autozone would have tested your alt for free to see if it was the problem.

    The Voltage Regulator needs to be checked next. Those are like $10 so no biggie there. Autozone can check that part too to see if it's bad.

    One thing that often happens is that the wires go bad. If the VR doesn't have a good hookup then nothing works. On my car the field wire had separated in the wiring harness. A quick soldering fix and everything was working great.

    -Mike

  5. #5
    FEP Super Member 69clark's Avatar
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    Default

    Well, I bought the voltage regulator and no dice. Still when I hook up the volt meter to the battery while running it doesn't seem to be jumping up to 13.5-14.5v. Am I over looking something simple? Maybe it is the battery?

    I started it a few times tonigh after putting the voltage regulator in and before I knew it the battery wouldn't crank it.
    Tom

    CAMMED & SLAMMED! For more build pics and updates: http://www.facebook.com/SINISBuilt


    For being "BUILT not BOUGHT" I am still broke!

  6. #6
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    I fought issues with a 79 capri like this and I just ended up going to a 3G from a 94/95 and wiring it up directly to get rid of all the other wiring
    99 gt with 03 cobra swap and tko600
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  7. #7
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    Default Test

    Start the car and note the battery voltage. Next turn on the high beams and the blower on high. If you have a rear defrost, turn that on too. If you start out at 12.5 volts and it drops down to 11.5 in about ten minutes, it's not charging. It should jump up to 13.5 - 14.5 volts and maybe slowly drift down. Turning the lights, blower and defrost should make it just back up. Oh, and by the way, it needs to be on high idle 1500-2500 RPMs to charge.
    Check how many AMPs the alternator is rated for. The high end of the stock ones were 60 amps. You can rebuild a stock one to 100 amps. Bad grounds or battery cables can prevent charging.
    Fox Body/3rd Gen MCA Gold Card Judge
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  8. #8

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    Quote Originally Posted by 69clark View Post
    Well, I bought the voltage regulator and no dice. Still when I hook up the volt meter to the battery while running it doesn't seem to be jumping up to 13.5-14.5v. Am I over looking something simple? Maybe it is the battery?

    I started it a few times tonigh after putting the voltage regulator in and before I knew it the battery wouldn't crank it.
    You have some bad wiring.

    You need to make sure the voltage regulator is hooked up correctly and test out all the wires to where they need to go. If you do not have a multimeter (or at least a test light) to check continuity, you need to get one.

    Edit: See image below

    -Mike
    Last edited by negusm; 04-17-2009 at 08:14 PM.

  9. #9
    FEP Super Member 69clark's Avatar
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    Okay, now I have some stuff to check out. BTW, all of this stuff was completely up to par last year, as I drove the car alot, now all of a sudden (after the winter) I am having this problem.
    Tom

    CAMMED & SLAMMED! For more build pics and updates: http://www.facebook.com/SINISBuilt


    For being "BUILT not BOUGHT" I am still broke!

  10. #10

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    That diagram is only correct for Fords that have alternator warning lights. Cars
    that have ammeter gauges connect the ignition to the regulator "S" terminal,
    and nothing to the regulator "I" terminal.
    Cheers,
    Jeff Cook

    '85 GT Hatch, 5-speed T-Top, Eibachs, Konis, & ARE 5-Spokes ... '85 GT Vert, CFI/AOD, all factory...
    '79 Fairmont StaWag, 5.0, 62K original miles ... '04 Azure Blue 40th Anny Mach 1, 37K original miles...
    2012 F150 S-Crew 4x4 5.0 "Blue Coyote"... 65 coupe, 289 auto, Pony interior ... '67 coupe 6-cyl 4-speed ...
    '68 Vert, Mexican block 307 4-speed... '71 Datsun 510 ...
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  11. #11

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    Quote Originally Posted by JACook View Post
    That diagram is only correct for Fords that have alternator warning lights. Cars
    that have ammeter gauges connect the ignition to the regulator "S" terminal,
    and nothing to the regulator "I" terminal.
    OK, I thought one of those wasn't connected. It looked right but I haven't looked at a VR connection in a while. Sorry for the confusion.

    -Mike

  12. #12

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    Quote Originally Posted by 69clark View Post
    Okay, now I have some stuff to check out. BTW, all of this stuff was completely up to par last year, as I drove the car alot, now all of a sudden (after the winter) I am having this problem.
    Not only do you have to make sure the VR is connected correctly, but the wire from the alt to the battery needs to be a SOLID connection. The high current will eventually burn through any wire that is fraying.

    -Mike

  13. #13

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    Does this look more correct?

  14. #14

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    That's conceptually correct. I would add that the alternator needs to have a ground
    wire connecting one of the ground studs on the case back to the main battery
    terminal ground point. The mounting bolts are not a good enough ground.

    And since I'm already being picky, there's also the connection from the alternator
    stator terminal to the carburetor choke heater.
    Cheers,
    Jeff Cook

    '85 GT Hatch, 5-speed T-Top, Eibachs, Konis, & ARE 5-Spokes ... '85 GT Vert, CFI/AOD, all factory...
    '79 Fairmont StaWag, 5.0, 62K original miles ... '04 Azure Blue 40th Anny Mach 1, 37K original miles...
    2012 F150 S-Crew 4x4 5.0 "Blue Coyote"... 65 coupe, 289 auto, Pony interior ... '67 coupe 6-cyl 4-speed ...
    '68 Vert, Mexican block 307 4-speed... '71 Datsun 510 ...
    And a 1-of-328 Deep Blue Pearl 2003 Marauder 4.6 DOHC, J-Mod, 4.10s and Lidio tune

  15. #15
    FEP Super Member 69clark's Avatar
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    Default

    Well basically the car has been fine up until now, so I now the wiring is all run to the correct places. If there is a wire that broke or is shorting out or something, then that maybe something to look into yet.

    However, its the weekend so I figured I would cruise to autozone and let them test it. Come to find out the alternator is not working. Now keep in mind, I just bought this one brand new. I know it happens (were brand new parts don't work) but this pisses me off. NAPA is gonna get this thing rammed up you know what.
    Tom

    CAMMED & SLAMMED! For more build pics and updates: http://www.facebook.com/SINISBuilt


    For being "BUILT not BOUGHT" I am still broke!

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