Toyota Repair: 98 Chevy Prism/Toyota Corolla Electrical problem, chevy prism, daytime running lights

Question
Dear Mr. Ritter, I own a 98 Chev. Prism which is basically a Corolla with a bowtie, 118,000 on the clock.  Start the engine, car runs great.  Turn on headlights, engine dies just like you turned off the ignition.  This car has daytime running lights so lights should come on automatically when car is started BUT the lights don't come on whether or not the emergency brake is on.  The e-brake indicator on the dash goes off & on as it should when brake is applied/released.  (The e-brake in "on" position normally turns headlights off).  If I use the turn signals with headlights off the signal will blink normally BUT the E-BRAKE idiot light flashes in tandem with the turn signal!?  Battery & alternator are OK, checked & cleaned every ground I could find, cleaned & checked positive battery terminal, checked ALL fuses (all ok), seems that power is not getting to the main DRL relay (under glovebox) because I can't get a test light to light when checking the connector so malfunction must be prior in the circuit.  (I also pulled the main DRL Relay but didn't see anything wrong with it, no burn marks, etc.)  Also switched out the DRLs in the 2 fuseboxes under the hood with new ones but it made no difference.  Pulled out the dimmer switch relay (also in the fusebox under hood) but that made no difference either. I even screwed around with the airbag system(!) (disconnected all the sensors & reconnected them) because the airbag light was flashing (as it has for 2 years), and after I put it all back together the airbag light wasn't flashing but the engine still dies when I turn on the headlights.  And yes, I checked the headlights and they are not burned out, connections are clean etc..  I can't get the headlights to go on no matter what I do, engine running or not, but the running lights operate--though they dim when I try to turn on the headlights.  And after I turn on the headlights (which don't come on) the radiator fan starts running and won't shut off unless I turn off ignition, and sometimes not even then--in which case I have to disconnect the battery!  Took car to local shop and ran diagnostic check, NO ERRORS!  My brother thinks its the headlight switch on steering column.  Car does not have a security (alarm) system that I can see.  When this thing started going screwy I could hear all sorts of relay noise coming from under the dash & hood when I turned ignition key to "on".  (It was not starter solenoid noise--and starter is about 4 months old.)  Any ideas you might have would be most welcome!  Thanks for your time!  Sincerely, Jim

Answer
Possibly a wiring problem, check all the wiring that goes to the fuse box on the inside on the left lower dash, look for any burned or discolored wiring and repair them as necessary, also check under the dash there is an electrical connector that is a ground bus, a lot of grounds go to this connector, this connector can develop corrosion on the inside and cause all kinds of problems, the connector is white and has a lot of white/black wires going into it, open the connector and check for corrosion on the terminals.