electrical wiring

Technical advice Q&A

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Jbv33670
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Joined: Mon Oct 19, 2020 9:01 am
France

#1 electrical wiring

Post by Jbv33670 » Fri Oct 23, 2020 5:52 am

Hello,

I have a question about the wiring diagram.

What is the normal path of the current?

Battery > ??????? > coil

Do you have a plan?

I have no power left on the coil while the starter is running...

thank you

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MarekH
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#2 Re: electrical wiring

Post by MarekH » Fri Oct 23, 2020 7:04 am

Make a loop all of the way from the battery positive terminal, through the coil and back to the battery negative terminal. This is why it is called an electrical circuit.

Typically, the circuit will go through the ignition switch, a relay, a ballast resistor as part of that loop.

kind regards
Marek

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abowie
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#3 Re: electrical wiring

Post by abowie » Fri Oct 23, 2020 7:20 am

Image

This is a very simplified diagram showing a typical ignition circuit with points.

The negative terminal of the battery connects to the car chassis (earth), and so does one side of the points, making the circuit.

Rick Astley's book "Classic British Car Electrical Systems" is an excellent reference.
Andrew.
881824, 1E21538. 889457. 1961 4.3l Mk2. 1975 XJS. 1962 MGB
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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Jbv33670
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#4 Re: electrical wiring

Post by Jbv33670 » Sat Oct 24, 2020 2:58 am

Thank you.

Will try.

Difficult to understand why I don’t have current on the coil and the ignition switch/starter works !

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Tom W
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#5 Re: electrical wiring

Post by Tom W » Sat Oct 24, 2020 6:21 am

What year is your car? Do you have points, or electronic ignition?

Are you saying you have power to the coil when the ignition is on, but none when the engine is cranking?
Tom
1970 S2 FHC

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Jbv33670
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#6 Re: electrical wiring

Post by Jbv33670 » Sat Oct 24, 2020 11:16 am

Tom W wrote:
Sat Oct 24, 2020 6:21 am
What year is your car? Do you have points, or electronic ignition?

Are you saying you have power to the coil when the ignition is on, but none when the engine is cranking?
Hello

1968.

No power on the coil, when the ignition is on and the engine cranking.

Will try this : viewtopic.php?f=3&t=16331&p=134008&hili ... il#p134008

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Tom W
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#7 Re: electrical wiring

Post by Tom W » Sat Oct 24, 2020 1:35 pm

Do any of the other ignition switched circuits work?
Tom
1970 S2 FHC

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Jbv33670
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#8 Re: electrical wiring

Post by Jbv33670 » Sun Oct 25, 2020 11:10 am

Yes

I have found the complete electrical wiring

Try tomorrow !

https://discourse-cdn.jag-lovers.com/or ... 3c09e.jpeg

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Logarius
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#9 Re: electrical wiring

Post by Logarius » Sun Jul 04, 2021 10:51 pm

Check the cables and connections, these are the most common reasons why it doesn't work in most of the times. If the reason is not in this, then most likely you either connected them wrong, or there is a part which is broken or not working. Try the connections first and see what you get. This is a very energy saving setup, and making it work will be very good. I saw something like this in the guide about the dual fuel deals https://www.simplyswitch.com/energy/gui ... uel-deals/, which was very interesting to know, a lot of useful information.
Last edited by Logarius on Sun Jul 18, 2021 9:35 pm, edited 1 time in total.

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abowie
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#10 Re: electrical wiring

Post by abowie » Mon Jul 05, 2021 9:11 pm

Jbv33670 wrote:
Sun Oct 25, 2020 11:10 am
Yes

I have found the complete electrical wiring

Try tomorrow !

https://discourse-cdn.jag-lovers.com/or ... 3c09e.jpeg
The power for the coil comes directly from the ignition switch. White wire.

If you drop the centre dash section down you will be able to access the back of the switch and quickly determine whether there is power at the switch and whether you have continuity between the switch and the coil.
Andrew.
881824, 1E21538. 889457. 1961 4.3l Mk2. 1975 XJS. 1962 MGB
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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