Volvo 1987 240dl ... hard wire the brake and tail

If you have a test light or voltmeter, turn park lights on and find the one wire on vehicle that is hot-it will almost surely be red or green, as the black is surely the ground wire. Now on the new socket, you need to know this: If those bulbs are two filament bulbs (one filament for park lights, and the other filament for brake or turn or both) the brake light and the turn light will be brighter than the park lights. You can tell the difference in brightness, and the brake lights are always brighter than the tail (or park) lights.
How many bulbs are on this socket? Do you have 2-filamet bulbs or just one filament bulbs? Maybe you can figure it out by looking at the other side, see how or which lights are for tails and which for brakes.

Pretty much universal is the color coding on vehicle lights. Brown, or another color with a brown tracer/stripe, is always the running lights. You wont see an all brown wire on these newer vehicles. Always another color with the proper color tracer. Brown=run & tail-tag lights, green is right turn and brake light, yellow is left turn and brake light, and black is the ground wire to the lights. Inside cab and under dash, You need look closer for these colored tracers.all ground wires are white. This is what I've found.

Your car has lost a ground wire somewhere on the dashboard.

lamp failure light on possible because the SECOND filament in your STOP/TAIL Light Bulb is burned out- change one side and check fail lamp again- repeat on other side- fail lamp works off of resistance-burned or blown bulb is only way it lights unless you have a wiring issue

TO SIMPLIFY,fuse box-pedal switch-tail light cluster,maybe something inbetween but hardly likely...start with cleaning the contacts for the brake bulbs as they may have verdigris on the brass connectors,then change the switch,then worry.

I have a 1990dl 240 volvo. Tell me if there is a brake lights relay in this model.
My brake lights don't work, fuse is ok, brake switch is ok, bulbs are ok.
thanks

Solder to the circuit board, just in case they interact with other circuits.

The tail light assemblies were a bad design in these cars. You need to take each socket out, and clean the contact points on them. Make sure they have a secure connection, and they haven't caused the bulbs to blow out.

The ignition module is located on the inner fender on the drivers side. I would check it to see if it is getting wet. It will cause the engine to not start.

if that doesn't help, you might want to check the bulbs. the damage might have shorted which burned out the bulbs. but you do have one wire that runs to the rear and splits off to the tail lights. the wire should run back to the head light switch via a fuse. the headlights have its own relay. but i hope it is just a fuse.

Check the switch by the foot pedal. Sometimes it can be adjusted or might need to be replaced. Disconnect it and check with ohm meter. MM85