How did my high beams kill my ignition? Options

[87m491]

After doing some bottom side work on my car last weekend (on ramps), and some dash bulb replacements, I went back topside to drive off the ramps (12 hours later) and absolutely no signs of life when ignition key is turned. No generator light, no oil light nada and of course no cranking. No fuses were blown. While the ignition switch hadn't exhibited symptoms of failing I figured I'd swap it out with a spare I had.

I swapped in the spare today. A bit of PITA so I went down an electrical check list before fully buttoning it up. Key on, dash lights check (generator and oil pressure, still stock incandescent bulbs) . Cranked over and instant start, check.

Installed the directional and wiper switch stalk so I can check the functioning turn signals, check. All the illumination LEDs I installed in the gauges this week, check. Running lights, check. Headlights up and check. High beams to check high beam LED, saw the high beam indicator light, heard a relay, click, momentary check, then the dash went dark!
Again, no fuses blown.

Now I am back to the symptoms that led me to think it was the ignition switch. No lights at all on the dash with key on and of course no cranking. Hazards work, 1st position headlight switch items, gauge illumination works, 2nd position headlights do not and fogs do not.

Data point, all of these items worked before the day before my first "dead electrical' experience last weekend. All wiring that I know of is stock.

Looks like 'll be getting friendly with my multimeter once the coming storm passes through the northeast.

Ideas BTDTs welcome.

[sportlicherFahrer]

I'd start with checking the high beam relay(believe it's called combination relay on wiring diagrams) and the headlight switch. I've had the high beam relay act similar to what you describe, but usually after a couple minutes of driving with the high beams on. However it did not kill all ignition power or other dash lights, just the headlights and high beam indicator. New relay cured my problem.

Carefully check for any connections behind the gauges as well. Sometimes it can be pretty easy to knock something out of place back there when working. Sudden problems like this can usually be traced back to the last area something was touched related to the problem. BTDT many times!