Question: My car SRK36640, I have a problem with my meter vitesse. I unscrewed the connector behind the dial there are 3 cable: red, blue, green.
red welded on the + terminal, the other 2 Dessoude. :o
there is a terminal 2 and A, for a blue wire and green. :?:
Thank for your help, Thierry

Answer: As far as I can see all Electronic speedo’s for all markets up to and including 1979 cars are as follows:
The Green wire is 12v ignition supply to terminal marked +
The Black wire is the earth and goes to terminal marked 2. 
The Red/Green wire is the pulse wire from the speedo transducer and goes to the terminal marked A. However there is a change for the 1980 cars for the California market in that the 12v ignition wire changed to white and there was an additional green/black wire for the lapsed mileage counter for the service light, which goes to terminal 31b. You will have to check if your Green wire is the 12v ignition and I have not a clue as to the other two.........
Hope this helps - any further questions please just ask.

Question: Thank you for your help.my problem was within the meter. deductively with your information. result is :
- a red wire = +
- blue wire = 2
- green wire = A
For information: the cables on my dashboard are:
- White = +
- Black = 2
- Red / green = A.
Thierry