I’m repurposing the 5 spare warning lights on the dash of my UK 1992 XJR-S, but have found that the Sport and Exhaust Temp lights don’t behave as simple fixed to earth indicators. Other warning lights are earthed on one side, and use +12V to turn them on. The Sport mode light (4.0L fitment) has the +12V side connected to some other warning lamps, and will light them up if the ground isn’t isolated. The Exhaust Temp warning (Japan only) works as expected with the ignition off but doesn’t light with the ignition on, so something is switching the earth off for that warning lamp.
I only have the 1992 MY Electrical schematic, but it seems to be only for the US market, and only V12. So, some fuse panels are swapped for the UK, no dim/dip relay, no Japanese market variations, no caravan warning light circuit, etc. Is there a more comprehensive schematic that covers all the variations?