Brown wire is the hot side.
"brown wire should light test light at the splice." maybe, depends on the flasher, some are normally closed and some are normally open. Jumper the flasher and push the hazard switch. All four T/S-Haz lights should come on steady.
Make sure your haz flasher is a heavy duty type rated for at least 6 T/S lights.
Just an FYI in case you don't already know this, here are the rest of the color codes in the ribbon cable to the T/S switch. purple- T/S feed from T/S flasher brown- haz flasher white- power feed from brake light switch dark blue-feed to RH T/S lamp light blue- feed to LH T/S lamp green- feed to RH T/S and brake lamp yellow- feed th LH T/S and brake lamp I don't recall from your previous post but I believe you have replaced the T/S switch. Be sure you have the right one. There are at least TWO different pinouts for the harmonica connector on the end of the ribbon cable.
After all that, I still think you have a bad, corroded or loose connection.