GTA clocks, voltage supply

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Hi Martin,

According to the manuals, The Red wire is 12v switched by the ign switch ..... it comes from the large connector on the LHS of the instrument panel ..... not regulated. However it is either not regulated, or it is regulated within the rev counter itself.
The Black is connected to 12v negative, and the yellow wire carries the tacho signal which I suspect, in the turbo engine, comes from the ECU,. It comes through the large LHS connector Pin 1..
I hope this answers your question. .

John

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I would expect the tacho signal to come from ECU too, but some one tolld me recently that it comes from the coil-pack (ignition power module).
Have a peek at the workshop manual, page C-11. Seems there is a 5v control signal from the ECU to it. I wonder what the output voltage from Tacho pin is?

I would expect the tacho signal to come from ECU too, but some one tolld me recently that it comes from the coil-pack (ignition power module).

Yes .... you are quite right Simon, someone did mention it some time ago, but I had forgotten about it, ......Thanks for that, ...... Martin, please note.

John