Umbra

I bought this 92 SC400 about a month or so back, it has a host of problems and interior is shot, however, my main concern right now is that my thermostat controls don't function (I know it's not a fuse because they light up, the buttons just don't do anything) and my taillights are out, I've tried replacing the bulb and same result... Essentially when I turn on my headlights the taillights don't come on at the half bright they're supposed to be at, but brakes and turn signals function fine. Any ideas on what this could be or at least a method for diagnoses that isn't gonna cost me a paycheck is greatly appreciated

tooshin

i had some what similar issue with the back light.
is your front head light extremely foggy any chance? when i bought mine SC300 couples month ago, i noticed that passenger side head light was developing heavy precipitation and after my passenger side rear tali light stopped working. i assumed it was caused by the shorted circuit due to water in front head light. i pulled out the front head light housing and found that the bulb was not secured thighly and there was gap. once i securely tightened, precipitation went away also the back light worked with out issue.

this video may help you if you want to upgrade your rear tail light. i found his website really useful.