Lotus Elan and Lotus Elan Plus 2 Forums

On my Sprint I want to add a switch with indicator light for the forcing function of the fan fixed to the radiator, but no diagram to my knowledge? and on the choice of the wiring color to adopt!
In auto electricity which wiring colors to use?

Thank you for your help

I dont think that an overide switch for an automated fan would be fitted as standard by any manufacturer. so there is probably not a standard for it. Does it operate by supplying +12v to the fan motor or is it used as a return to earth ? This might determine the base colour for the wire you choose.

I do not understand your explanation (I am not competent) so I asked to know the colors used to recognize which harness it is by observing the colors and if necessary to probe!
(such as; purple = klacson or black = grounded)
So I hope to make myself understood as well. Thank you

geni wrote:On my Sprint I want to add a switch with indicator light for the forcing function of the fan fixed to the radiator, but no diagram to my knowledge? and on the choice of the wiring color to adopt!
In auto electricity which wiring colors to use?

Thank you for your help

Geni,
You have asked the same question before and Phil Harrison provided a circuit diagram with wiring colours. Have a look here......

viewtopic.php?f=38&t=45760&start=0

The previous post (linked) is very useful, but depends on how much you know already.

if you google lucas wiring colours you may find useful help.


There is a book by John Dickens ("Automotive electrics, a practical guide"), £15 and is fairly new. I do not have a copy, so cannot say if it is good.. but it may help.
the lucas standard (Lotus may have followed it, maybe not always) would be for a black wire with green stripe (tracer) to supply power from the otter switch (usually in the radiator, with two wires from it) to the fan itself. My understanding is that the black tells you that the cable is heading to earth and the green stripe that it is a 12v supply to an accessory (the fan) which is then earthed. The green I believe also tells you that the supply is only live with the ignition on.


from google translate...
Il y a un livre de John Dickens ("Electricité automobile, un guide pratique"). Je n'ai pas de copie, je ne peux donc pas dire si elle est bonne .. mais cela peut aider - nous ne savons pas déjà combien vous en savez.
la norme lucas (Lotus peut l'avoir suivie, peut-être pas toujours) serait qu'un fil noir avec une bande verte (traceur) alimente le commutateur de loutre (généralement dans le radiateur, avec deux fils) vers le ventilateur lui-même. Ma compréhension est que le noir vous indique que le câble se dirige vers la terre et la bande verte qu'il s'agit d'une alimentation 12v à un accessoire (le ventilateur) qui est ensuite mis à la terre. Le vert, je crois, vous indique également que l'alimentation n'est active qu'avec le contact.

geni wrote:I do not understand your explanation (I am not competent) so I asked to know the colors used to recognize which harness it is by observing the colors and if necessary to probe!
(such as; purple = klacson or black = grounded)
So I hope to make myself understood as well. Thank you

There is no certainty that a 50 years old car has not been modified a bit along the way.

First thing I would try to do is to identify the radiator fan relay (there probably is one so as not to overload the temperature switch), then check how it is driven by the temperature switch (most likely the temperature switch conveys a ground when active, that is hot) : this may be done by checking the switch with a voltmeter (or possibly a light on a wire...). If indeed the rad fan relay is activated by a ground return, which you can then check by touching that wire with a grounded wire and hear the relay clicking (and the fan starting if all is still connected), then the override switch will only be a matter of bringing an extra ground on that same terminal but controlled by your override switch.

Photos of the parts would be useful if you want practical help, starting with the temperature switch (and other relevant parts you deem appropriate).