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.

[Superhawk996]

Grounds

[87m491]

Grounds

An all encompassing response that is simultaneously so broad that it my actually point to a solution or be void of any real utility.

While I have a very hard time understanding schematics, I'm pretty sure the ignition switch houses no grounds. I think the generator and oil pressure idiot lights have different grounds for each and I know the headlight motors and starter certainly do. The likelihood of each of those simultaneously failing during the same 10 second interval have to be pretty high yet the occurrence would have one believe they are somehow daisy chained.

"Grounds" will certainly be part of the investigative process.

[Superhawk996]

Grounds

An all encompassing response that is simultaneously so broad that it my actually point to a solution or be void of any real utility.

While I have a very hard time understanding schematics, I'm pretty sure the ignition switch houses no grounds. I think the generator and oil pressure idiot lights have different grounds for each and I know the headlight motors and starter certainly do. The likelihood of each of those simultaneously failing during the same 10 second interval have to be pretty high yet the occurrence would have one believe they are somehow daisy chained.

"Grounds" will certainly be part of the investigative process.

I apologize for being non specific or flippant but based on the symptoms and the number of things that you messed with, it is hard to be more specific but sure sounds like you disturbed a ground circuit or multiple circuits.

There are common grounds behind up behind the instrument panel which you may have disturbed. This ground is needed for the high beam / combination relay. When you mentioned the high beams worked momentarily then stopped and the dash went dark. This is the ground I was thinking of when I replied.

The generator (alternator) and the oil pressure lights are indeed on a common ground path via the engine case and then thru the engine transmission ground strap to the chassis. Incidentally, this is also the ground path for the starter motor. You don’t mention what you were doing under the vehicle before all these problems started.


Let’s do a reset:

The number of problems that you described is going to be tough to address with a singular solution since many of those circuits don’t share a common 12v feed or a common ground.

The very first thing I would check is to make sure you have solid connections at the battery + and all the red wires and the connection from battery negative to the chassis. I would also make sure the ground strap between the engine and the chassis is connected. I don’t think this is the issue since you did get a start after swapping the ignition switch - your call depending on what you did under the car. If the engine ground strap isn’t present - the clutch cable becomes the ground path (not a very good one - but it becomes ground none the less).

You may have multiple problems depending on what you did under the car, behind the instruments, and swapping / installing ignition switch and stalk switches. The best way to address them is to tackle one issue - like no switched power via the ignition key (no oil, no Gen, no-start). Begin methodically troubleshooting this singular problem with a multimeter and schematic for your model year vehicle.

It is quite likely that in the process of troubleshooting that, you will discover the source of the other problems as well assuming they have some shared circuitry such as a bad ground path or potentially a bad 12v + power feed from the battery.

Hope that is more helpful.