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Points Or No Points

Discussion in 'Early CJ5 and CJ6 Tech' started by Holty, Jan 14, 2021.

  1. Holty

    Holty New Member

    my 1977 cj5 304 has a distributor with points and condenser.
    It is not starting, so I wanted to change them and my parts house
    tells me 77 did not take points and condenser. So, what was oem?
    Sounds like somebody before me made a change or this engine is older.
    If needed I will take the points out and match them up with something.
    Any suggestions on what points go in there?
     
  2. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    '75-77 AMC and Jeep came with the Prestolite electronic ignition, the BID (breakerless inductive discharge - or something like that). Very troublesome - no loss. Very often replaced with an older distributor (Delco points type) or a newer distributor (Motorcraft Duraspark electronic ignition). There are also aftermarket GM-type electronic distributors with the coil in the distributor cap, but the 304 never came from the factory with those.

    A points distributor from a '73 or '74 drops in, and that's likely what you have. That's a Delco, and it should have a window in the distributor cap that you can raise, reach through with an Allen key and set the point gap.
    1973 JEEP CJ5 5.0L 304cid V8 Distributor Cap | RockAuto
    1973 JEEP CJ5 5.0L 304cid V8 Ignition Breaker Points | RockAuto

    If it has points, the only other it could be is a speed part, like a Mallory.
     
    Last edited: Jan 14, 2021
  3. jeepdaddy2000

    jeepdaddy2000 Active Member

    First question is do you have spark?
    If so, the points aren't your issue.
    If not, then there are a couple of simple checks you can do.
    WITH THE POINTS OPEN and using a test light:
    1 Do you have power to the + (battery) side of the coil? If not, then your issue is between the battery and the coil. If so, then:
    Do you have power on the - side of the coil? If not, then the coil is bad. If so, then:
    Do you have power at the distributor? If not, then the - wire is bad. If so, then:
    Do you have power at the points arm?. If not, then the interior pigtail/connection block is bad/grounding. If so, then:
    You have a grounding issue with the points contact. Either they are remaining open, closed, or the contact face is dirty.
    Clean the faces and reset the gap. Don't forget to reset the timing last.

    With the points closed, you should be able to open
     
    Ol Fogie likes this.
  4. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    I would point out that the Prestolite system used no ballast resistor. If you are running the original coil, you need a ballast resistor with points ignition. Won't be the immediate source of your problem, but you need it for the points, condensor, and coil to last.

    Good advice from jeepdaddy200 - first see if you have spark.
     
  5. Holty

    Holty New Member

    ok. my cap does have a window.
    i will check on delco points.
    thanks
     
  6. Holty

    Holty New Member

    low spark.
    it does have a ballast resistor.
    coil is good but i need to take it further like you said.
     
  7. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    If the spark is weak, how do you know the coil is good?
     
  8. Holty

    Holty New Member

    the coil is new.
    i will follow jeepdaddys suggestions to maybe pinpoint
    my problem. thanks to everyone
     
  9. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    I think this ends "the points and make a spark." If you try making a spark by manually opening the points, make sure there's no circuit through your body. Use an insulated tool and don't ground yourself.
     
  10. 3b a runnin

    3b a runnin Active Member 2023 Sponsor 2022 Sponsor

    I always suspect new parts as faulty, especially if that is when the trouble started
     
    47v6 likes this.
  11. jeepdaddy2000

    jeepdaddy2000 Active Member

    You won't get shocked. The points only run 12 volts (9 actually after the ballast resistor). you can turn the ignition on and open and close them all day with your fingernail.

    Now the secondary coil wire is a different matter.

    Low spark can be caused by a couple of things......
    1 Coil wired backwards. + to battery side. - to dist side.
    2 Poor points contact area. File the point faces and adjust the arm so the faces close completely. Don't forget to reset the gap (dwell) when you are done.
    3 Bad wire connector. Inspect the coil to dist wire and power wire inside the dist female ends to insure the wires aren't broken at the connectors.
    4 Poor point ground. Inspect any ground straps. Many distributors use a small woven copper ground strap between the breaker plate and the dist housing.
    5 Low voltage to the coil. Check voltage throughout the system. It should not be below 9 volts. Check the rear of the ballast resistor to insure the resistance wire isn't damaged.
    6 Bad coil. You can swap out the one you just installed for the old one and see if there is a difference.

    Opening the points with your fingernail should give a nice fat spark when the coil secondary wire is held 1/8" from the block.
     
  12. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member


    Draw the circuit out- the points/condenser are in the return path for the high voltage side- if the condenser is bad the juice is jumping the plug gap & point both in series so probably thousands of volts present on the points.
     
    Ol Fogie likes this.
  13. jeepdaddy2000

    jeepdaddy2000 Active Member

    There is approximately 12 volts at the points. Period.

    The coil produces a high secondary charge by using a collapsing magnetic field on the primary side. The two circuits are not connected. The only way to receive a secondary shock is by getting too close to the end of the secondary coil wire, an unfortunate but not uncommon situation that is not related to contact with the points.

    The condensers job is to buffer the primary voltage to the points, extending their life.

    If there were any danger of high voltage electrical shock at the points, it would be a common and known issue.

    I have personally used my fingers to work points to produce secondary spark more times than I can remember and have never experienced even a tingle.
     
    dozerjim and Rick Whitson like this.
  14. Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    I pull the coil wire out of the cap, hold it next to the block, with the ignition on, and open the points manually, it should spark. That easy. Like jeepdaddy says. We would put a Dollar bill between the points when closed and pull it through, cleans off any crap in there and it would fire in the 60's a lot of times. Good Luck.
     
    dozerjim likes this.