Fitting a Voltmeter to a 2CV
Clubs and Charlestons are fitted with voltmeters in the instrument panel - Citroen calls them "battery condition meters". They indicate whether your alternator is charging the battery correctly, giving early warning of alternator, voltage regulator or battery failure. It's easy to fit one to Specials and Dollies. Voltmeters are available at accessory shops together with plastic mounting pods which can sit on the parcel shelf (picture at foot of page) or brackets which hang below it. (Alternatively, if you can find one, you could replace the small instrument panel with a Club / Charleston type, but that's not dealt with here.)

Read the instructions which come with your voltmeter. Typically there will be 3 electrical terminals on it and it should be connected in such a way that it is only 'on' when the ignition is on. Some of the wiring is provided on Dollies and Specials and will be taped up behind the instrument panel.

Before you start, disconnect the battery. Remove the instrument panel by undoing the four crosshead screws and pull the panel towards you, far enough to see the wires at the back, taking care not to disconnect any. Don't lose the four rubber washers which fit on the screws between the back of the instrument panel and the body panel to which it is screwed.

Look for an unused female spade terminal with a mauve insulator. (Over time the mauve insulators are incllined to fade and it may appear white).
This terminal should be connected to the positive (+) terminal of the voltmeter so you will probably need to extend the wire far enough to reach the position where you intend to fit it. In the event that you can't find the mauve terminal you can use a two-way ("piggy back") spade adaptor on the MAUVE terminal of the fuel gauge (not the yellow one, picture below).

If you're worried about delving behind the instrument panel, an alternative supply for the positive (+) terminal of the voltmeter is the wiring behind the starter switch. The wire with the mauve sleeve is the one which is live with ignition on so tapping into that wire with a scotchlock or chocolate block connector will give you the appropriate feed.

The negative (-) terminal of the voltmeter should be connected to a good earthing point on the car body and this could be a piggy back connector on the earth terminal on the back of the instrument panel (see photo) or a screw which goes into the car bodywork, near where you intend to mount the instrument, using a ring connector. Make sure the new wiring is well insulated and use proper connectors, not tape joints!!. At the other end of the extensions you will need to fit the type of terminal required by your voltmeter.

A third terminal on the voltmeter will be for its illumination and this can be connected into the speedo bulb with a piggy back spade terminal, scotchlock or chocolate block connector, depending on how the bulb is wired in the speedo. A flying lead is used in the example below but this varies according to age of car. If you decided against removing the instrument panel, an alternative source for this connection is the light switch. The wire with a mauve (may appear white or grey) sleeve is the one for the sidelights so, with a suitable ring connector, adding your wire to that terminal of the switch will give the desired result. Being able to see the voltmeter at night is probably more essential than during daylight so that the charging system can be monitored while all your lights are on.

When the wiring is complete, and you're happy that it is all effectively insulated, reconnect the battery. The voltmeter shouldn't indicate until the ignition is turned on. With ignition on it should read around 12v. Start the engine and when revs rise above tickover the reading should increase to around 14v. Any variation from this should be investigated. When you're happy that it's working correctly you can mount your voltmeter as desired and refit the instrument panel, ensuring that the four rubber washers are fitted between the instrument panel and the car body. (These washers prevent the various wires being crushed between the back of the instrument panel and the car bodywork.)
This is a suitable type of pod to mount your voltmeter on the parcel shelf (or a clock, as in the picture). Alternatively you can obtain brackets which can be hung under the shelf using self-tapping screws (which in turn could be used as the earth connection for the instrument).
see also wiring diagrams
FITTING A CLOCK is very similar to the above procedure except that the +ve feed must come from a source which is permanently live, such as the wire with the black sleeve on the back of the starter switch. And remember, the clock will be running permanently and could flatten the battery if the car isn't used regularly.
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