Hello! I drive a Jaguar from the 1980s, and while driving the car I notice that all of the electronic signs on the dashboard (Empty/Full/Light on/Seatbelt off) are on at the same time, even though I drive with a full tank. What sort of problem is this?
Loose/corroded/broken or otherwise electrical wiring and connectors can result in your problem.
A short (bare wire rubbing on metal or wire across wire) or perhaps a bad switch could also cause the fault.
Even a bad sending unit may do it.
Check all visible electrical connections first.
I have a drivers power seat (yeh, like most of you) and due to constant repositioning between my wife and myself, the electrical connector under the seat (for the side mounted air bag in the seat back) works loose and causes the light to come on the dash.
When the air bag light is displayed on the dash the system is disabled.
To look at the connector you’d never think it’s loose and not making contact.
I fixed this fault by disconnecting the two connectors, sprayed electrical contact cleaner in each side, plugged them back together and taped the connector. No more losing contact.