Ignition Capacitor/Condensor

Interior and Electrical

  1. David Clark

    David Clark Well-Known Member

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    Ok, Both my Dart and Aspen have a Capacitor/Condenser (Back in the day, we always just called it a condenser) coming off the ignition coils. I can't find this part listed anywhere in Rock Auto's Parts list for either the 76 Dart or 79 Aspen (both /6's) and the one on the aspen is SHOT, the wire is broke off coming out of it.

    Anyone have a clue what it would be listed under in the Rock Auto Catalog?? or a part number for the dang things. They have a Generator Capacitor Listed but it looks nothing like what I have on these cars.
     
  2. kkritsilas

    kkritsilas Well-Known Member

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    They have one under the 1972 Valiant. I'm not sure that you even need one, as the ignition coil is connected to the Igintiion Control Module (ICM), which most likely has its own capacitor built in.

    The ignition capacitor is mostly for points type ignitions, from what I recall, but could be wrong about that. Supposed to help the points live longer by preventing arcing as the points opened/closed.
     
    Last edited: Mar 14, 2016
  3. David Clark

    David Clark Well-Known Member

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    Tough Question, the Ignition Control Module I got from Rock Auto (Correct Part number) has 4 Pins in it but the one I took off had 5 Pins in it. Not even sure if that's the correct part now. Come to think of it, the ICM I took off the Dart hard 5 Pins on it too and the replacement part has 4 pins.
     
  4. kkritsilas

    kkritsilas Well-Known Member

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    The number of pins on the ignition module has to do with what kind of ballast resistor is used. The two section ballast resistor used a 5 pin connector, the one section capacitor used a 4 pin. I think the 4 pin module just doesn't use the second section of the ballast resistor even if it is there.
     
  5. Captain Caravelle

    Captain Caravelle Moderator--Mopar Maniac

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  6. Aspen500

    Aspen500 Well-Known Member

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    The condenser on the coil is only for radio interference suppression for the AM band. It doesn't have anything to do with the ignition system itself.
    The one that was in the points distributor was for the ignition, basically to "soak up" the current when the points opened to prevent arcing and burning of the contact points. More or less like an electrical shock absorber,,,,,,,,,,,,kind of.

    I looked everywhere I could think of in the parts catalog but it only shows one listed for car line M-Z (Omni/Horizon) Actually it's listed under "the following parts are not illustrated". For what it's worth, that p/n is 3501915.
    Later I'll look through it a little closer. Could be in a different section or, not in there at all. Hmmmmmm.
     
    Last edited: Mar 14, 2016
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  7. David Clark

    David Clark Well-Known Member

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    Both my Dart and Aspen have the Double Ballast Resister Setup on them. And All 4 Terminals are plugged in on both of them. Yes Capt Caravelle, that's the Ignition Control Module that I have on both cars now, the ones I pulled off originally have 5 pins in them though. Both cars have a condensor/capacitor attached to the Ignition Coil. (Well the Aspen no longer does as the wire broke off on the capacitor/condenser.)
    --- Post updated ---
    To my knowledge both of these cars I have, have the Points type ignition system.
     
  8. Cordoba1

    Cordoba1 Well-Known Member

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    Hi David: Two things - If your cars have the ignition controller picture above, then you don't have a points-type distributor. You likely have a hall-effect distributor, which uses a magnet to trigger the ignition controller, which in turn collapses the field in the coil to send spark to the plugs. Secondly; ignition system condensers are not specific to any particular setup. That is to say, any will do! They sell these in the Help! section of many auto part stores. Or; next time you're at your local pick-and-pull; nab one from any older car.
     
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  9. Darth-Car

    Darth-Car Well-Known Member

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    Yes you probably have a 5 pin ignition module from the factory. The after-market modules come with a slip that says even though they have four pins they will work fine in a five pin car. That being said my 77 Volare, years ago had a 5 pin module. I replaced it with a 4 pin module. the car did not run right. I purchased the legitimate 5 pin module from the stealership, and the car ran correctly. -Your experience may vary.
     
  10. David Clark

    David Clark Well-Known Member

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    Thanks, I guess the 4 Pin one will work, It's started just fine after I replaced it (along with some other parts). Same with the Dart, had a 5 Pin but running fine so far with the 4 pin one. Gonna have to drop the Tranny on it now, Clutch is Locked up from sitting for 10 yrs I guess. UGH. Will Not disengage at all.

    Thanks for the input on the Capacitor/condenser stuff.
     
  11. BudW

    BudW Moderator Staff Member

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    The part the OP has in question: – the parts big end attaching to ground and wire end attaches to one of the ignition coil wires (battery or “+”, I think) – is called both a radio suppressor, a capacitor or also called a condenser.

    In 1977 the official part number for the “radio suppression” ignition coil capacitor is 3501735.
    Vehicles without radios did not come with this part and it is considered to be “radio” part, not an ignition system part - in the official part books. Chrysler has used this same part (not necessarily the same part number) sense before mid ‘60s to present.

    I looked up the same part number for 1988 and part number is 4048646 (also called a radio noise suppressor).


    Vehicles with points also have one inside of the distributer (as well as one on coil for radio), but it is to increase the lifespan of points. It is a capacitor, but for some reason the commonly used name is condenser.


    --- Post updated ---
    The 4 pin and 5 pin ICU’s can/will interchange.
    When they were first used, they used the lower resistance half of dual ballast resistor to give higher voltage upon startup.

    They found out that wasn’t necessary, so that section was bypassed completely on all newer ICU’s (and vehicles).
    (The extra pin has nothing to do with the capacitor mentioned in the first post)


    If you have a car with a dual ballast resistor, and car will not start until you let off of starter mode OR if starts on start mode but dies after you let off – then you have bad ballast resistor.

    Back in the 70’s & 80’s, it was always a good idea to have a spare ballast, ICU and voltage regulator in your trunk.
    Now days, those parts seem to be more reliable.

    BudW

    Picture added

    Radio suppresor.jpg
     
    Last edited: Mar 20, 2016
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  12. Leizurtime

    Leizurtime Well-Known Member

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    Forgive me for saying so, but this is a partially correct statement. A hall effect switch, is a bit different than the "magnetic pick-up style" system that utilizes the ignition module pictured. Points were standard until 1972, then in 1973, a majority of mopars were upgraded to an electronic ignition system utilizing a magnetic pickup coil, reluctor, and ignition module. This particular system determines ignition timing by magnetic interference as the reluctor turns in front of the pick up and is prominent on all of the FMJ body cars.

    A hall effect switch came after the magnetic pickup style. It contains a magnetic sensor that reads off of a reciprocating disc with notches cut out. As a notch passes in front of the optical sensor it determines ignition timing. The disc is usually located on the front of the engine, mounted on the crankshaft in factory applications.

    There are aftermarket versions which are for upgrading distributors. Perhaps some manufacturers in the past built off of the old distributor template, I'm not sure. The most optimal means of reading timing is off of the crankshaft and most hall effects I've seen use a crank trigger. I have considered one of the kits they sell out there, Pertronix has one, as my understanding is hall effect sensors provide an even more accurate ignition trigger. However, the magnetic style is more than adequate.

    Anyways, its a more modern technology than the magnetic pickup style. Not sure if it was ever offered on an FMJ car. Perhaps on some late 80's versions, but I don't think so.
     
    Last edited: Jan 20, 2017
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