I went through this earlier this year, also my rear wiper didn't work either. Both the wiper motor and brake light assembly worked properly when disconnected / isolated and tested separately. Started troubleshooting by reworking the grounds under the center console and under the rear near the...
got one of these. the multiple inserts allow for a variety of sizes from pop cans up to Nalgene liters
https://www.bh3dprinting.com/product/91-97-toyota-landcruiser-lx450-91-97-double-cup-holder/