Fitting a condenser

in Ignition System

Internally fitted condenser

A typical internal condenser has its lead going to the terminal of the breaker and is earthed by the screw that fixes the condenser to the baseplate. Condenser with its leads removed from the baseplate.

The condenser is a small electrical device connected across the -breaker points in the distributor.

It helps to give a crisper spark at the plugs and also retards erosion of the -breaker points.

If the points are badly eroded, and a general ignition check (See Checking the high-tension circuit) has eliminated other causes, suspect a faulty condenser.

Condenser removed with its leads from the baseplate.

The condenser may be fitted outside the distributor, or inside on the -breaker baseplate; on a few cars it is fitted into the wiring somewhere near the distributor. In most cases it is easy to get at, but on cars with poor access you may have to remove the distributor (See Removing and refitting the distributor).

A magnetic screwdriver, or a dab of grease on a screwdriver blade, is useful for fitting small screws.

Fitting to a Lucas distributor

Replacing the condenser, which is mounted internally, is simple; but with the earlier type of breaker take care to reassemble th terminal post correctly.

Unclip and remove the distributor cap. Unscrew the terminal-post nut. Lift off the plastic insulating washer and the leads to the points and condenser. Remove the screw holding the condenser to the baseplate.

Tighten the securing screw firmly - it also earths the condenser.

When reassembling the distributor, be careful to fit the leads underneath the plastic insulator.

If they are replaced above it the points will be earthed and the ignition will not work.

Tighten the securing screw firmly - it also earths the condenser.

Fitting to other types of distributor

The condenser in the Ford Motor-craft and AC Delco distributors is internal.

Unclip the cap (on some AC Delco types the cap is held by screws) and remove it. On the Ford distributor, slacken the terminal screw and slide out the spade terminal.

Detach the condenser lead on the AC Delco type by pressing the -breaker spring to release it. Take out the condenser securing screw and lift the unit from the baseplate.

The condenser on the Nippon Denso, Mitsubishi, Bosch and Ducellier distributors can be mounted on the outside.

AC Delco

The condenser terminal is clipped under the -breaker spring.


The condenser is mounted outside, held by a single screw and clip.


The condenser lead is connected by a spade terminal

Removing condensers that are externally mounted is a simple operation, and there is no need to remove the distributor cap.

On these types, the condenser leads can be freed from exterior terminals, and the condensers removed by undoing single retaining screws.

Although on the Bosch distributor the condenser is external, you still have to remove the distributor cap, rotor arm and condensation shield.


A terminal block connects the points to the condenser lead.


The internal condenser lead is held by a terminal nut.

Nippon Denso

The condenser is secured by a single screw.

Unfasten the lead from the -breaker points to the terminal block. On the outside of the distributor, remove the terminal-block securing screw and bracket, then the screw securing the condenser to the distributor body. Lift the assembly clear.

Read more

Overhauling a Bosch distributor

Inspecting the ignition system

A typical ignition system. The most usual type of coil, with the HT connection at one end in the...

How engine timing works

Distributor The distributor both sends the HT current to the correct sparkplug and ensures that ...

Checking the high-tension circuit

The high-tension circuit Make sure that all the wiring connections are sound. Always take great ...

We're making the ultimate video course.

Get it →

You can preview the video course here