About my XJ-S 1980 pre-HE

Tachometer:

When I bought the cat, the tachometer and a lot of other stuffs did not work. I wasted lot of time to repair it.: Put it out of the car, it works ! Put it back, not works !
So the wires are fubar.
With the help of jag-lovers list (thank a lot ) and the Palm's book I succeed to fit it and I'm writing this page because other should have the same problem.

4 wires: The last one is disconnected to drive direct to the (-) of the coil !How to repair ?

On the engine, under the gas control  tower, you have the "resistor ballast" 4 wires arriving on one side. The last one is white with blue line. Disconnect it and connect it directly to the minus(-) side of coil (with the help of a 20 cm wire). If the new wire is badly connected then it will avoid the engine to run. (Personally, I connected it to a switch witch finish to the ground . Only rabbit are stolen here !).


Back of the instrument panel:

The blue/white wire drive to the "trigger" of the tachometer (~) (Usually the wire inside is yellow).
To test your tacho out of the car:
+ ==>+12V
- ==>     0V
~==> ~12V (Ok I used the ~9V delivered by .. my modem power supply)
50 Hz means 500 rmp 2x(50x60/12).

The extra non standard wire is connected to the galvanometer: one day my tacho will be able to write S.O.S. in radar wave field !