Coil Voltage -Checking & Fixing

Discussion in 'Technical' started by aldig, Aug 23, 2010.

  1. aldig

    aldig Member

    Joined:
    Jun 7, 2009
    Messages:
    28
    Likes Received:
    0
    Trophy Points:
    25
    Location:
    New York
    Vehicle:
    1971 Grabber
    Bought a 72 w/302, converted to pertronix electronic ignition before I bought it. How do I check to assure the coil is getting the proper voltage? What is the proper voltage? I've been told it needs to have 12 volts for electronic ignition. With my key to the on position, I connect a tester red from tester to positive on coil and black from tester to negative on coil. It reads 4 volts. If I need 12 volts, how do I do this? I've heard Mavericks do and dont have a ballast resistor (mustang forum). Also heard there to run a wire from the ignition to coil. Any help appreciated. Car runs smooth but feels held back.....that makes sense if I'm not getting enough to the coil
     
  2. rthomas771

    rthomas771 Member

    Joined:
    Jan 22, 2008
    Messages:
    8,064
    Likes Received:
    958
    Trophy Points:
    498
    Garage:
    1
    Location:
    GA
    Vehicle:
    '74 Maverick 302 5-Speed.'60 Falcon V8. '63.5 Falcon HT
    The Maverick, like all 60-70’s Fords, uses a resistor wire instead of a ballast resistor. Mopar used the ballast resistor. Just find a switch 12v wire that is hot in the 'Run/Start' position. Make sure it's cold when the key is in the ‘Off/Acc’ position.
     
  3. aldig

    aldig Member

    Joined:
    Jun 7, 2009
    Messages:
    28
    Likes Received:
    0
    Trophy Points:
    25
    Location:
    New York
    Vehicle:
    1971 Grabber
    Thanks. So are you saying I do need 12 volts and the solution is to find a wire that is hot when the key is on (and off when key is off).
     
  4. rthomas771

    rthomas771 Member

    Joined:
    Jan 22, 2008
    Messages:
    8,064
    Likes Received:
    958
    Trophy Points:
    498
    Garage:
    1
    Location:
    GA
    Vehicle:
    '74 Maverick 302 5-Speed.'60 Falcon V8. '63.5 Falcon HT
    Thats all you need...and the correct coil to handle 12v
     
  5. mojo

    mojo "Everett"- Senior Citizen Supporting Member

    Joined:
    Jul 20, 2009
    Messages:
    5,272
    Likes Received:
    833
    Trophy Points:
    513
    Garage:
    1
    Location:
    Chicago
    Vehicle:
    73 Comet GT-302 4bl
    What abt Ford DurasparkII? My car was converted B4 I bought it but seems to run quite well getting abt 6.5 volts.
     
  6. rthomas771

    rthomas771 Member

    Joined:
    Jan 22, 2008
    Messages:
    8,064
    Likes Received:
    958
    Trophy Points:
    498
    Garage:
    1
    Location:
    GA
    Vehicle:
    '74 Maverick 302 5-Speed.'60 Falcon V8. '63.5 Falcon HT
    The Dura-Spark II module takes 12v...But the coil takes 6-8 volts. Nothing wrong with 6-8v with a Dura-Spark II. The Pretronix likes 12v better than 6-8 volts.
     
  7. bmcdaniel

    bmcdaniel Senile Member

    Joined:
    Jul 2, 2002
    Messages:
    6,822
    Likes Received:
    681
    Trophy Points:
    318
    Location:
    York. PA
    Vehicle:
    '70 Maverick Grabber
    On mine, the only wire I've ever found that has 12 volts during START and RUN, but not in ACC is the ignition wire. Maybe later years are different. You can use the ignition wire to energize a relay whose NO contact is connected to the battery, the relay C terminal connects to your ignition. Don't forget to measure the coil's primary resistance, needs to be at least 1.5 ohms, IIRC, or the Pertronix will cook.
     
  8. Earl Branham

    Earl Branham Certified Old Fart

    Joined:
    Mar 9, 2002
    Messages:
    6,367
    Likes Received:
    201
    Trophy Points:
    218
    Garage:
    1
    Location:
    Lugoff, SC
    Vehicle:
    '69.5 Maverick 302, T-5, Grabber Green
    I went to the back of the switch and replaced the wire with a 12ga wire to the coil, replacing the resistor wire. BTW, it is a large soft pink wire.
     

Share This Page