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914World.com _ 914World Garage _ Distributor condensor wire

Posted by: 911914 Apr 21 2005, 09:30 PM

'74 2.0 liter. Mallory ignition but with points. Noticed the wire from the condensor to the distributor is cut. Car runs fine. Any ideas on this? What do the condensor do?? Is this a problem? New owner to 914's.
Thanks.

Posted by: Dave_Darling Apr 21 2005, 11:55 PM

The condensor acts as a "shock absorber" to the points, sort of. (Pun not intended.) The large currents that wind up going through the coil can really fry a set of points in short order. The condensor is there to absorb some of that current before it gets to the points, and therefor prolong their life. The points wire goes from the points, to the condensor, and then from the condensor, to the coil. I believe that the circuit goes through the condensor, rather than simply joining at the one "side" of the condensor.

If the wire is simply cut, I don't know why the engine would still run...

--DD

Posted by: ArtechnikA Apr 22 2005, 04:53 AM

far be it from me to contradict Dr Dave, but the condensor is not in series with the points signal. rather, the condensor is also attached to the points, and to ground. the "Shock Absorber" simile is quite apt tho.

CDI ignitions don't use Condensors, since their current draw on the points is low; tell us more about this "Mallory Ignition"

Posted by: drive-ability Apr 22 2005, 07:15 PM

Condenser,
I didn't work with points much but Its at the electrical end of the ignition faze. The unit is there to as stated to absorb free electrical energy left over. My tune up teacher taught me the "minus minus minus rule".
If metal is being removed (-) from the negative(-) side of the points, the set up is under(-) condensed. You need a higher rated condenser in the distributor.

Notice! Yes its useless information

Posted by: 914GT Apr 22 2005, 10:30 PM

QUOTE (drive-ability @ Apr 22 2005, 06:15 PM)
Condenser,
I didn't work with points much but Its at the electrical end of the ignition faze. The unit is there to as stated to absorb free electrical energy left over. My tune up teacher taught me the "minus minus minus rule".
If metal is being removed (-) from the negative(-) side of the points, the set up is under(-) condensed. You need a higher rated condenser in the distributor.

Notice! Yes its useless information

Now here's some more useless info. You're closer to the right explanation. The word 'condenser' is an old-fashioned term from early days of radio, it's really a capacitor. The cap really doesn't do much to affect the current in the coil. The coil is like a big inductor, and once current gets going through inductance it basically likes to stay that way because there's energy stored in a magnetic field around it. But if that current is stopped abruptly (like when the points open) that magnetic field collapses. Since that energy has to go somewhere, it ends up as a high voltage across the points. This causes arcing which burns the points. The 'condenser' acts to short out the high voltage arcing to protect the points, but this still is a lot like the 'shock absorber' analogy that Dave explained.