Need Light Retainer Relay 85961-24010
 

Hoping someone has one to spare.
Mine doesn't generate the ground signal to the tail light relay (the headlight portion works). Also knocks out the instrument panel - but brake lights work.

Meanwhile, I'm scrutinizing the circuit board. The taillight circuitry has less electrical protection on the input from the light switch than the headlight input. Plus the headlight portion's output (to it's relay) has dual drive transistors vs. 1 for the taillight.
There are over 40 parts. I'll start with the drive transistor.
Can always add in a separate relay near the retainer relay -- like I did for the starter (which had no relay).