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> How did my high beams kill my ignition?
87m491
post Sep 14 2023, 05:31 PM
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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.
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87m491
post Sep 18 2023, 06:39 AM
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So I dug in this weekend and still no definitive answers but a running driving car.

1 checked that all the Wehrle style relays were good and each was OK
2 rechecked all fuses, all OK
3 Checked all cluster grounds and cleaned each down to the brass button
Pass side headlight cluster was a little dodgy and the transmission body strap looked so crusty it took me a second to see it apart from the road grime. Tested OK but I replaced it anyway.
4 checked the old seat belt relay bypass, still in good shape.

Still, all "through key" electrics dead. (running lights, but not headlights, instrument lights and hazards all OK)

I was not "seeing" power through the new ignition switch out to the ancillaries. So I tested the new switch to see if I accidentally fried it. It tested good. WTH?

I decided to jumper the ignition connectors directly;
1 Jumper 30 to 15 and I immediately get oil light (no generator light) and fuel gauge and hear FP run
2 jumper 30 to starter, get cranking
3 jumper 30 to X and get full headlight activation. Again what gives?
(IMG:http://www.914world.com/bbs2/uploads_offsite/i.imgur.com-14731-1695040790.1.jpg)
So I take the next logical step and use a screw driver(always wanted to do this) and jumpered 30 and the starter with all other connections jumpered and the car fires right up!

The first 2-3 times I retried this, the generator light did not come on but the car was charging at the battery. I tried the hazards and the front blinkers were out of synch so I may check that relay again. Generator light now comes on normally.

I cycled the high and low beams and no weirdness at all save the high beam indicator light does not illuminate. (Non led bulb tests good)

So scratching my head I reinstalled the ignition switch and turn signal switches and all seems back to normal.

Remaining oddities,
Solid 14V charge rate indicated in dash gauge and confirmed at battery. (How much is too much?)

directional idiot light remains illuminated 100% of the time. Gets more intense and blinks properly when directionals/hazards activated.

High beam indicator will not light (bulb is good) when high beams activated.

Current flow diagram shows a link between these two lights and I assume something is back feeding the directional to cause the permanent light but I'm not smart enough to know what.

if anyone has seen this LMK
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Superhawk996
post Sep 18 2023, 08:31 AM
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QUOTE(87m491 @ Sep 18 2023, 08:39 AM) *


The first 2-3 times I retried this, the generator light did not come on but the car was charging at the battery. I tried the hazards and the front blinkers were out of synch so I may check that relay again. Generator light now comes on normally.

if anyone has seen this LMK

Check fuse 9 (late cars) and fuse 8 (early). Make sure fuse terminals are clean and holding the fuse tight.

This fuse provides the current path to turn on the generator/alternator bulb at key in to bootstrap the alternator.

Loose fuses in these positions can cause all sorts of wonky behaviours.
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