Alright, I will be as brief as possible.
1. when flash high beams, only left one comes on. Have rewired from low to high(worked for a while), cleaned all terminals, replaced headlight, and relay. No go and bulb out light now on.
2. 'check engine' light comes on. Where can I get diagnostic reader so I can see what the code fault is? See below for what happens next.
3. 1/2 after 'check engine' light come on, when I flash highbeam- wipers come on without using wiper switch, does not go off until 10 min. later when flick on high/low beams. At the same time using left or right tuen signal make some instrument lights come on in sync with turn signal. When I get everything to return to normal by flicking between high and low beams, all is fine.
I have also checked all known grounds.
Is this the alternator brushes? Headlight switch? What is going on? Is my electrical system having a meltdown?
My brick is my only means of transport, total failure would be huge PITA.
I would greatly appreciate any knowledge, insight or instruction. Cost would be appreciated as well, things are tight.

Much, much Thanks in advance.

Rob Mac
1989 740 GL sedan, 5 speed, B230F, near 210,000 miles