OK, so we all know what points do. We all know that the Pertronix modules do the same thing but better (lets not go there!) But can someone give me the lowdown on how the Pertronix units work? Are they some sort of reed switch arrangement that gets pulses from a magnet? I think I have read somewhere that when you install these Pertronix units the module itself replaces the points and that you press a magnetised cam onto the shaft. Is this the case? My car does have the Pertronix modules (single dist, twin coil euro) and I just want to know what I have and how they work. Also I have the coils mounted in the alloy heat sinks. Underneath the coil is a small electronic module. The output of the Pertronix plugs into this module (two connectors labelled "W and G" in my photo) and then the other side of the module runs off to the coil etc. Next big question, what does this extra electronic module do? It is labelled Magneti Marelli BKL 1A. That number doesn't score any hits on a F-Caht search but it does on the web. I can't find anything concrete about the module but it may be an amplifier of sorts. So can someone please shed some light on this much discussed peice of our Ferrari ignitions? Image Unavailable, Please Login
Look up "Hall Effect" and you will get a defination of how it works. I don't know how your Euro is set up but I had an aftermarket Pertronix unit set up in my dizzy. It does not have an external electronic box . There are 2 wires that come out of mine and 1 goes to a +12v source and the other goes to one of the coils. I think that your setup uses a similar hall effect sensor but it is not a Pertronix unit. I believe MM made up there own unit. All the Pertronix unit does is close a switch to fire the coil.
Your picture is of the standard Marelli "Plex" ignition amplifier module mounted on a coil heat sink. This is standard not only for your car, but also Fiat, Lancia and Alfa from 1979 on in the US. It was a popular aftermarket upgrade for earlier Alfa and Fiat applications. The "ignition pickup" located on the breaker plate is a coil whose field is disturbed by the passage of metal tangs on the distributor shaft. The spacing between the tangs and the Marelli ignition pickup is set by non-metallic (plastic or brass) feeler gauges. The two things that fail are that the insulation to the pickup inside the distributor gets old and flakes off, allowing the wires to touch and intermittent fire, then no fire occurs, the other being a failure of that module you have pictured. That module is sold in nearly every auto parts store in the US, as it's a standard GM replacement part. Your pickup in the Marelli distributor is not a Pertronix. It requires the module to amplify and set the dwell (length) of the coil ground duration, hence the spark. It has a metal trigger that narrows to the end of a screwdriver-like blade shape as it passes over the central, metal exposed core of the MarelliPlex ignition pickup. The Pertronix unit, which replaces the MarelliPlex ignition pickup, is completely self contained and requires no amplifier or any other module between the red and black wired coming from the Pertronix to the coil. HTH.
