I recently purchased an ‘84 XJ6. It runs well. However, the wipers, brake lights, and horn do not work. I need suggestions outside of fuses on where to start with my diagnosis? Thank you!

 

Here's something on horns

Horn Circuit Checklist


For brake lights the easiest place to begin (after checking bulbs and sockets) is checking for 12v at the brake light switch with the key "on" on the light green wire and then 12v at the green/purple wire with the pedal pressed. If no 12v at the green/purple wire, the switch is bad.

If the switch is OK then go to the bulb failure module in the trunk and jump all three of the green/purple wires together. If the brake lights now work, then you bulb failure module is bad. Take notes before disconnecting the wires so you be sure to reconnect them properly

Cheers
DD

 

there is an inline fuse for the horn above the battery. You can't miss it, the fuse is inside a plastic fuse holder with thick brown wires.

to open the fuse holder, press both ends as you turn the holder halves against each other, one half clockwise, one half counter-clockwise. The holder gets melted and distorted with the engine heat so it might take some force and WD40 to release the two halves.