so my 85 XJS coupe is back to life but in my haste to get rid of most of the Lucas stuff in the car, i mustve jerked a power wire somewhere.
things that no longer work

power windows
electric door locks
headlights
tail lights
brake lights
license plate light

now i yanked the headlight relay so im pretty certain thats why the headlights dont work anymore. im curious as to what sort of amperage the headlights draw and whether i can get away with running a toggle switch set rated for the appropriate amp's to run the headlights on one switch, the tails on a seperate switch. the brake lights im more curious about. do the brake lights run off a relay or do they get power through the brake pedal switch? im thinking of just running power through the brake switch to run the brake lights.

power windows and electric locks are more pressing since its hot as crap outside and thieves are a thing. i get the feeling they share a power source somewhere.

any help would be tremendously appreciated. ive got a chassis diagram around here somewhere but cant for the life of me find it.

 

No sure of your market, but some fuses are involved there.

The brake lights on my '85 had no relay.

The amps for the headlights (and the others on that circuit) is easy. Total the wattage, divide by the voltage used (12v in this case) and the answer is the amps. Dont forget the small parkers, number plate lamps, and Hi beams.

 

alright. replaced a fuse and flipped a couple connectors and now the headlights work, the brake lights work, and the power windows work.

still no LP light, no tails, and no reverse light. nor did changing the electric lock switch work

but thats progress right?