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View Full Version : oh ye electrical gremlin... go away (please) - RESOLVED! bad LED!



toadster
07-25-2024, 11:02 PM
ok - the car is (was) fully working IMHO before paint - two electrical gremlins bugging me

1. high beams on by default - already chasing this one https://thefactoryfiveforum.com/showthread.php?49480-weird-scenario-when-i-turn-on-the-lights-high-beams-are-on-by-default wiring looks good, but still digging

2. right turn signal flashes all the dash lights - yes, you read that correctly...

using the left turn signal is just perfect, left lights blink on/off or hi/low (if lights are on), and the left indicator blinks in the speedhut speedo

setup:

RT Turn Signal setup
IDIDIT relay for high/low beam on the stalk
RF wire harness
Speedhut wire harness
locking hazard button

we've pulled the lower dash/stereo out to get more room - trying 'not' to pull the dash if we don't really have to
also took the speedometer out of the dash to see inside a bit more

somehow we're determining that the right turn flasher is somehow tied into the dash lights - trying to trace everything

here's the testing (over testing IMHO) on the wiring

as would be expected if you hook up a white dash light wire to pink flash wire
all 4 lights flash on/off - but so does the dash



hazard light activity:
turn the light switch on - dash lights turn on - press hazard, 4 hazards flash as expected, dash is lit (no flashing)
turn the lights off - dash lights turn off - press hazard, 4 hazards flash and the dash flashes


turn signal activity:
key on, activate left turn signal, left turn signals blink, left turn signal blinks in speedo
key on, activate rt turn signal, rt turn signals blink, rt turn signal blinks in speedo, AND all dash lights blink


connect green left turn to pink hazard, left blinks as hazard, front right parking light goes out
blue hzd rt connect to pink hzd flash - all 4 blink


light switch turned on green left side turn - connect to pink hzd
left front blinks low/hi flash, right front blinks on/off flash
left rear blinks low/hi flash, right rear stays on low light, no flash


light switch turned on blue right side turn - connect to pink hzd
left front stays at low light no flash, right front does low/hi flash
left rear stays at low light no flash, right rear does low/hi flash


light switch turned off green left side turn - connect to pink hzd
left front blinks on/off, right front is off
left rear blinks on/off, right rear is off


light switch turned off blue right side turn - connect to pink hzd
all 4 lights flash on/off
dash flashes with lights

very odd how some of the corner lights flash differently depending on wire connections - obviously not fully wired as expected as the hazards are wired in pairs (front/rear, left/right) so that may be the odd blinking modes

really perplexed that when the right turn signal is used, the dash flashes...

I know it's a matter of tracing wires, but any first thoughts? very odd!!

Nigel Allen
07-26-2024, 05:31 AM
G'day Todd,
Most of these, if not all will be grounding issues. This is particularly the case when unrelated lamps glow. It is a case of positive voltages unable to flow directly to ground, and instead finding their way to ground through other lamps, in turn causing them to glow. Check all grounding to chassis of head, tail and indicator lamps at vehicle corners. Take time to think of what might have been disturbed during prep for paint. Don't hesitate to reach out.

Best of luck,

Nige

Nigel Allen
07-26-2024, 05:41 AM
Take the front right hand indicator lamp out of its socket and see if the dash light/ front right indicator issue goes away. From your description it would appear that right indicator and parking light circuit are shorted together. One obvious place for this to happen is in the lamp holder.

Nige

Jeff Kleiner
07-26-2024, 09:02 AM
Wacky behavior like this is often one of two things...either a weak ground at one of the lamps which will allow current to backflow as it seeks ground OR a bulb that is clocked incorrectly in it's socket and which will allow both terminals of the bulb to touch the contacts in the socket. I'd start with the easiest path by taking bulbs out of the parking light sockets and see if that cures it.

EDIT: After reading Nigel's comments it looks like he and I are both on the same page ;)

Jeff

toadster
07-26-2024, 09:36 AM
thanks guys! hopefully that will be some quick testing :)

Mike.Bray
07-26-2024, 10:10 AM
Groundliness is next to Godliness.

toadster
07-26-2024, 10:35 AM
Groundliness is next to Godliness.

LOL yeah

Blitzboy54
07-26-2024, 10:50 AM
Seriously, I over grounded everything. Can’t have too many (maybe you can but I have not yet found the limit)

CraigS
07-26-2024, 03:41 PM
Also look at grounding bolts threaded in to the frame that may have been removed and then that area was painted. Or a light socket pulled from the body, left hanging, and got some paint into it.

CraigS
07-26-2024, 03:50 PM
Seriously, I over grounded everything. Can have too many (maybe you can but I have not yet found the limit)

I agree, decades ago I was a Lexus tech and we had a car w/ very weird auto trans shifting. Tried this and that and finally ordered a trans to be replaced under warranty. Still shifted weird. Finally found that a ground wire that bolted to the back of the intake plenum (cross wise V6 so plenum to firewall clearance was about 3/4inch) was attached but the bolt was not tight. History showed that about 4 months prior a brake line had been replaced which required removing that ground wire to get it out of the car. We were pretty sure that the bolt had been installed finger tight but the final wrench tightening (maybe one full turn) had been overlooked.

Tbev
07-27-2024, 04:49 AM
I chased a wacky turn signal issue I was having for over a month. It ended up being the bulb like Nigel and Jeff said. Lesson learned-always start with the easiest solution first.

toadster
07-27-2024, 12:24 PM
pulled the front right led bulb, dash flashing goes away - doing more testing :)

thanks guys!

Nigel Allen
07-27-2024, 12:28 PM
Try putting the left hand lamp in there, as it had been working okay.

Jeff Kleiner
07-27-2024, 12:29 PM
pulled the front right led bulb, dash flashing goes away - doing more testing :)

thanks guys!

Put it back in clcoked correctly.

Jeff

Mike.Bray
07-27-2024, 06:41 PM
https://www.imagecoast.com/images/MichaelBray1/fbimg17202788314081.jpg

toadster
07-28-2024, 08:01 PM
ok - looks to be one bad LED 'upgrade' bulb that I have - one of them works, the bad one replicates issues side to side and on the dash - SO weird!

so back to incandescent until I get a replacement...

it's simply unbelievable - one bad bulb caused the dash to flash (depending on what side it was on), it caused my hazard light itself NOT to flash, AND it killed my horn! WTH??!

swapped out to good bulbs and everything works perfectly!

WOWSERS! Thanks all for your help!

Nigel Allen
07-28-2024, 08:40 PM
Wow, great outcome. The horn fault has me beat.

toadster
07-29-2024, 01:17 AM
totally agree! no clue why the horn quit at the same time!

Tbev
07-29-2024, 04:51 AM
Glad you figured it out. I was having similar strange issues and after a month of testing and researching it ended up being an LED turn signal bulb that was not turned all the way to the left. It's so frustrating when you are that close to being finished and something so minor sets you back.

BRRT
07-30-2024, 09:44 AM
That is insane! Glad you found it.
Nigel and Kleiner have super powers.