"trouble" light comes on when I press brake pedal. Also flashes in time to left turn signal .

I thought this was fixed on my1990 240 DL after the last electrical track down at our local Volvo experts shop. I have the Owners Manual (in good shape) and a new Haynes Manual. What I'm getting is that it is almost like a "check engine" light, to check the bulbs and the related fuses. Which I've done and it stopped it 1 or 2 times. The lights are all on, and flash as they are meant to. It's just worrisome considering the problems I've had so far, related to electrical mostly.
Also, I can't keep going back to the Volvo repair facility--their hourly shop rate is too much.
My regular mechanic group which took care of it for years, and sold it to me, doesn't really want to work on Volvos. The same as other shops. BMW, Mercedes, etc.., OK. But Volvo?.....

 

FOUND IT, I think. Happened to notice one of the taillight bulbs was out the next evening. fouind he # in the manual, local Auto Parts looked it up in American English Trying to get the cover off to get the old one out was the trick. The photo an wording in manual was unclear. Turned out the plastic lens needed moved backward to gain access. When trying to get the bulb out, I had crushed the glass part, but used curved plies to grab the metal part and twist it out. At least the 2 new ones showed me what they looked like--they have 2 nibs at the bottom are are push and twist. However, trying to get the new one back in with my big fingers, it fell out on pavement and broke. ! Not sure how to proceed, but...