Up date
ok my 2004 s type is still giving me nightmares
had bad ignition , alarm and so on no parts available in new Zealand
up date
Have installed a new keyless entry alarm system
With push button start
Good news car starts i can drive it it dose everything it s'pose to do
the only problem now is when i lock and unlock car i can not get indicators to flash
Hazard and indicators work
Have tested indicator wring at bulbs and have power all the time
is this correct
Thanking you

 

Yes. Almost all the electrical systems on the S-type work on switched earth with a constant live.
For example in this case the indicators have a switched earth feed from the front and rear electronics module.
In addition almost all the switches etc on the car also use a low current switched earth system.
This makes any non-standard modifications somewhat complicated.
Here is a link to the official wiring diagrams for your carthat clearly show this. Just download from the list under the 'Electronics' heading the one for your model year :

JagRepair.com - Jaguar Repair Information Resource

Mellow