What do they do? They mess up all the time! Switch to electronic ignition. Now that the smarta$$ answer is out of the way...... .....the points are the mechanical device that transmits spark to the plug wires through the distributor cap. Note when you take the distributor cap off you will see that the center of the shaft looks like and 8 sided (V8)nut-called the distributor cam. The points open/shut as the distributor rotates allowing spark to transmit through the wires. Think of them as an electrical switch. I don't have a clue what a condenser does to be honest with you. I just know to replace it when you replace points. Don't forget the little grease where the points meet the distributor cam. It keeps the points from wearing out so quickly. Make sure you have the point gap set correctly. I used to set mine at .017 if memory is correct. Seth
Actually the above description is incorrect. What is described is more like the rotor function. As the distributor turns and the points open current is interrupted to the primary side of the coil resulting in a collapse in the secondary coil winding. The collapse is the magnetic induction within the coil (think transformer) this creates the high voltage and current necessary to jump the gap of the spark plug. This is delivered to the spark plug via the coil wire, rotor, distributor cap and plug wire. The condenser is actually a capacitor. The condenser prevents arcing across the points during the collapse of the secondary winding of the coil. Without the condenser the point contacts will burn up quickly due to arcing.
The points allow the ignition coil to charge when they are in the closed position. Look at the distributor cam that the points rub against. A lot of flat areas with some bumps, one bump for each cylinder of the engine. The points are electrically between the (-) ignition coil terminal and ground. The (+) side of the coil has + voltage from the key applied. When the points are closed (contacts touching) due to the point's rubbing block being on a flat spot of the distributor cam, electrical current flows through the coil and builds up a magnetic field in the coil. The distributor cam is spinning. When a cam "bump" causes the points to open current stops flowing through the coil, the magnetic field collapses, and induces a voltage into the coil windings. The coil is a form of step-up transformer so the induced voltage is stepped up to several thousand times it's original voltage and exits the coil out of the large high tension lead on top which in turn goes back to the ditributor center post. The high voltage at the center post is "distributed" to the appropriate spark plug wire via the rotor which is turning along with cam inside the distributor.
I was trying to be as basic as possible in my answer since he had no idea what they were. I wonder whose response he understands now?
OK to be basic but "the points are the mechanical device that transmits spark to the plug wires through the distributor cap" doesn't define them correctly.
Points are a mechanical device. In hindsight, transmits was the wrong word to use in the balance of the statement. How about..."they tell the coil when to send fire to the plugs." ? I still don't totally understand how a condenser works. I know what I have been told it does, It sounds like an electrical filter?
K.i.s.s. To answer your question very simply: Points open to trigger the coil to send spark. The spark is sent to the correct plug by the distributer cap/Rotor. The condenser is like a "shock absorber", it soaks up electrical current to prevent the points from arcing when they open up, this gives them a long happy life! I hope this is simple and clear! Dave