Builds bcomnes' 1991 3FE FJ80 Build (1 Viewer)

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So here is an interesting problem:


- I installed LED tail lights.
- my radio started dimming when I was in drive, as if I had my lights on when they weren’t.
- I diagnosed that when the car is running, I get a small phantom voltage on my illumination circuit (dash lights, dimmer circuit) but only when the car is in drive or
Lower gear and running.
- with led tail lights the voltage fluctuates from 3-4 volts.
- with incandescent, that voltage drops to about 1 volt.
- with the lights on, it’s a solid 12ish volts as it should be.

Not sure the source yet, but I’m definitely getting it on the illumination wire behind the radio.

Anyone have any ideas where the source of this voltage could be coming from when in drive?

I don’t think it’s a grounding issue, in the sense I have checked with various ground points with no difference, unless something else is grounding through this circuit.
 
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Full set of interior and exterior LEDs for a 91 FJ80 arrived from superbrightleds.com (except for a couple wedge types that were out of stock, and high-low beam pairs).

Opted for LED color matching over color filters, and warm white LED where a white incandescent was used before.


View attachment 2511632
Just screenshot me your order for this! Haha (no, seriously) I need to replace basically every interior building in my 91 as well. Most in my gauge cluster no longer work
 
Joined
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Just screenshot me your order for this! Haha (no, seriously) I need to replace basically every interior building in my 91 as well. Most in my gauge cluster no longer work
See Builds - bcomnes' 1991 3FE FJ80 Build - https://forum.ih8mud.com/threads/bcomnes-1991-3fe-fj80-build.1188065/page-2

I swapped the tail lights for Amazon product which worked better.

I'm not 100% sold on LEDs tbh. They work fine for dash replacements, backup and blink replacements. But the tail lights have caused all sorts of weirdness with just finding compatible LEDs. I'm contemplating switching back to incandescent dash lights, keeping exterior LEDs, and interior lighting LEDS (map, cabin, glovebox).

Some other cons for LEDs:

- The Neo wedge LEDs don't have the same light characteristics as the tiny OEM bulbs. Some things don't light up evenly.
- The LEDS are a lot brighter, kinda too bright
- The tail light LEDs caused phantom voltages in my illumination circuit, had to compensate behind my double DIN to fix the dimmer.

Also, I need to re-order the Green LEDs. They are way too green. Need to get warm white and use the green lens condoms to get the OEM lighting tint.
 
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Messages
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See Builds - bcomnes' 1991 3FE FJ80 Build - https://forum.ih8mud.com/threads/bcomnes-1991-3fe-fj80-build.1188065/page-2

I swapped the tail lights for Amazon product which worked better.

I'm not 100% sold on LEDs tbh. They work fine for dash replacements, backup and blink replacements. But the tail lights have caused all sorts of weirdness with just finding compatible LEDs. I'm contemplating switching back to incandescent dash lights, keeping exterior LEDs, and interior lighting LEDS (map, cabin, glovebox).

Some other cons for LEDs:

- The Neo wedge LEDs don't have the same light characteristics as the tiny OEM bulbs. Some things don't light up evenly.
- The LEDS are a lot brighter, kinda too bright
- The tail light LEDs caused phantom voltages in my illumination circuit, had to compensate behind my double DIN to fix the dimmer.

Also, I need to re-order the Green LEDs. They are way too green. Need to get warm white and use the green lens condoms to get the OEM lighting tint.
You’re the man! thanks for such meticulous record keeping on documenting your build, wish I would have done the same with mine.. now I don’t even want to know how much I’ve spent but I also plan on never getting rid of it. I’m weighing between leds as well, if only there was a way to add a dimmable option..
 
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They are dimmable, but if you mix them with incandescent (especially the 74s) you get inconsistent brightness.

I guess tldr:

If you really love LEDS, get LEDS for everything, and you will have some oddities to work through.

If you sort of like LEDs where they count, get them for: headlights, side lights, parking lights, blinkers (+flasher relay), backup, cabin/map/glovebox. Maybe get them for tail/brake, but you might need resistors, or troubleshoot phantom voltages on your illumination circuit (at least on mine). Leave the dash as incandescent.

I have a mixed dash right now, and can't decide what to do lol.
 
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Went out with @leonard_nemoy this weekend. Hit up birthing caves and saw the second cave this time. Lots of fun.

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