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Ballast Resistor On F134??

Discussion in 'Early CJ5 and CJ6 Tech' started by Paulietools, Oct 21, 2019.

  1. Paulietools

    Paulietools New Member

    I'm trying to troubleshoot a no spark issue on my 1967 CJ5. It still has the original F134 motor.
    While reading the universal manual I downloaded off the web it stated "only the Dauntless V6 has a ballast resistor"
    If this is true then someone added an extra ballast resistor that is not needed or required.
    I have not replaced the points or the condenser yet, I'm trying to eliminate what I think is major problem first.
    Can anyone confirm my thoughts about the ballast resistor?
    Thanks in advance.
     
    Paulietools, Oct 21, 2019
    #1
  2. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Depends on whether the coil is stock or not- should be written on it whether or not it requires an external resister.
     
    Howard Eisenhauer, Oct 21, 2019
    #2
    Jrobz23 likes this.
  3. Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    My 64 didn't have a ballast resistor, but an internal resistor on the coil. I used a 66 wiring harness, it had a ballast resister in it, so I just hooded the wires together to eliminate the resister.
     
    Rick Whitson, Oct 22, 2019
    #3
  4. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    What do you see as that "major problem" and why?
     
    PeteL, Oct 22, 2019
    #4
  5. Glenn

    Glenn Kinda grumpy old man Staff Member

    Does the coil say external resistor required?
     
    Glenn, Oct 22, 2019
    #5
  6. Jrobz23

    Jrobz23 Member

    Check the basics first.

    Confirm you got good ground
    Confirm you have voltage at the coil
    Confirm your main source wire ohms out
     
    Jrobz23, Oct 22, 2019
    #6
  7. gunner

    gunner Member

    Several replies and no mention of the Pertronix, so I'll rattle that cage.

    Made for a significant improvement on my Fhead. Can be searched here on the forum- lots of opinions in both directions.

    But no need for a resistor with the Pertronix. Give it the full 12 volts.
     
    gunner, Oct 22, 2019
    #7
    mike starck likes this.
  8. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Depends on the coil, I don't have the instruction for the unit I bought in front of me but I'm pretty sure they say not to remove the resister if there was on there to begin with.
     
    Howard Eisenhauer, Oct 22, 2019
    #8
    Jrobz23 likes this.
  9. Jrobz23

    Jrobz23 Member

    I wouldn’t start my spark troubleshooting at the distributor, I’d end it there.
     
    Jrobz23, Oct 22, 2019
    #9
  10. mike starck

    mike starck Member

    That is correct per there instructions.However if you install a pertronix coil with internal resistor you may remove ballast resistor if you choose. Which I did. mike
     
    mike starck, Oct 22, 2019
    #10
  11. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Except that an accurate and effective diagnostic process depends on knowing that all tune-up items are within spec... before beginning.
     
    PeteL, Oct 22, 2019
    #11
  12. kenb

    kenb Cleverly disguised as a responsible adult

    Most ignition systems with ballast resistors bypass the resistor for starting. So I don't see the harm in jumping around it for a test.
     
    kenb, Oct 22, 2019
    #12
    Rick Whitson likes this.
  13. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    True, & I certainly would, but you're simply replacing the external resister with the internal one. My points (pun intended :)) are that if you remove the resister from the circuit that has a coil that requires an external resister then you're ignoring the instructions, voiding the warrantee & playing test pilot.

    YMMV bit it could be e as short as the end of the driveway :(
     
    Howard Eisenhauer, Oct 22, 2019
    #13
  14. mike starck

    mike starck Member

    Not at all.the instructions clearly state that IF you replace the coil with a Pertronix coil with internal resistor you may bypass the ballast resistor. You have to read the instructions that come with the NEW coil to get to that point. Perfectly OK :) BTW I have done so on both my V-6 engines and a Ford V-8.
     
    mike starck, Oct 22, 2019
    #14
  15. Paulietools

    Paulietools New Member

    Thank you all for the replies. I have not pulled anything apart yet, I am in the process of purchasing the replacements parts so that I can just replace everything and (hopefully) start with good components.
    That was the reason for my question. The OEM replacement coils I am seeing are all internal resistor so I wanted to clarify before I got the wrong one.

    I am glad you went ahead and rattled the cage on the Pertronix. I was just reading a few of the threads and thinking that might be the way for me to go and avoid some of the known issues with points. I know that we won't be driving this vehicle on a daily basis so I was worried about the points corroding.

    Looks like I have a decision to make before I buy the new parts I need.
     
    Paulietools, Oct 29, 2019
    #15