Blind spot monitor

[Lkh]

Blind spot monitor light on dashboard on.  Dealership saying replace mirrors for $700 - $900 ugh 

options?

[1990LS400]

That sounds odd since problems with BSM are more commonly caused by a defective or misaligned radar unit in the rear quarter panel.  Unfortunately, replacing a rear BSM radar unit is pretty expensive too.

The only component in the external mirrors related to BSM are the indicators in the mirror glass.  A wiring harness connector simply plugs into those.  Are you mirror glasses damaged?  The BSM indicator in my driver side external mirror still worked even after the mirror was trashed in a collision with both the glass and the housing broken badly.