gixer2000
Retrofit or Bust
Yeah that works but involves building an entire harness for the brakes and blinker circuits. I was looking to make it happen easily without running wire everywhere. But it's probably the easiest option.
LED Turn Signals?
- Thread starter 1111ExpyEL1111
- Start date
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Muddy Bean
Full Access Members
Don’t stop looking because if you figure out a cleaner way to do it I’m absolutely interested. Because I tow my truck 15,000 miles a year behind my tour bus, and my tour bus has separate turns and brakes, it really would be best for me to make my truck the same way. Plus, we sometimes park on on ramps for the night with semi trucks since we are 65 feet long and I have a switch that activates my hazards on full brightness but not blink for extra visibility when parked for the night.
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Sent from my iPhone using Tapatalk Pro
Axle Folly
Member
I have been working on a plan, yet to be executed. If you can help me poke holes in it before I get too far into tearing into my vehicle, I'd appreciate it!
My plan is to get a tail light converter module (either Tekonsha 118158 or Curt 56196) and stuff it in the tailgate lift access opening, conveniently located behind the driver's-side tail light assembly. This gets me separate brake and turn signals.
Then, I would enlarge the hole for the reverse light (921) and install a Amber/White switchback (7444na). I'd wire the reverse light circuit to the white, and the turn signals to the amber.
Since I don't necessarily trust all of the added connections or the magic converter box, I would drill another hole in the tail light assembly for that little 921 bulb, and wire that to the existing stop/turn circuit that I tapped the magic converter box off of. My hope is that this does a couple things: 1. Avoids hyperflash/bulb out message with new LED turn signal, as the incandescent bulb would be used, 2. Offers some redundancy should the converter box fail, and 3. Would help force me to check that the LED bulbs were still working at least as frequently as my 921 bulbs burnt out!
My plan is to get a tail light converter module (either Tekonsha 118158 or Curt 56196) and stuff it in the tailgate lift access opening, conveniently located behind the driver's-side tail light assembly. This gets me separate brake and turn signals.
Then, I would enlarge the hole for the reverse light (921) and install a Amber/White switchback (7444na). I'd wire the reverse light circuit to the white, and the turn signals to the amber.
Since I don't necessarily trust all of the added connections or the magic converter box, I would drill another hole in the tail light assembly for that little 921 bulb, and wire that to the existing stop/turn circuit that I tapped the magic converter box off of. My hope is that this does a couple things: 1. Avoids hyperflash/bulb out message with new LED turn signal, as the incandescent bulb would be used, 2. Offers some redundancy should the converter box fail, and 3. Would help force me to check that the LED bulbs were still working at least as frequently as my 921 bulbs burnt out!
Muddy Bean
Full Access Members
Axle,
You have some good ideas there for sure. I especially like the switchback for reverse LED idea and may try to experiment with that myself a bit. I’m still not 100% convinced that the converter box will work the way we are hoping because of my experience with that exact box doing weird stuff. I’m also not sure how you’re going to wire the switchback LED but I’m super interested to watch the process. Someone here might be more familiar with how a switchback works (wiring wise) and could chime in.
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You have some good ideas there for sure. I especially like the switchback for reverse LED idea and may try to experiment with that myself a bit. I’m still not 100% convinced that the converter box will work the way we are hoping because of my experience with that exact box doing weird stuff. I’m also not sure how you’re going to wire the switchback LED but I’m super interested to watch the process. Someone here might be more familiar with how a switchback works (wiring wise) and could chime in.
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deweysmith
Full Access Members
Switchback is pretty simple, I thought I explained it earlier in this thread, but it might have been a different one. EDIT: I kinda did over on post #35.
Basically, there are two circuits in the vehicle that go to the turn signal harness. 4 contacts on the bulb and two filaments inside the bulb, one is a low (15W?) draw and one is a high (30W?) draw. When parking lamps are on, the BCM grounds the low circuit, closing it and lighting up the smaller filament for dim amber lights. When the signal is flashing, it repeatedly grounds the other circuit, causing that circuit to close and the larger filament to glow much brighter. As far as I know there is no situation where they are both powered.
Switchback LEDs take advantage of this by having two separate circuits in them with two sets of LEDs. They are the same brightness, usually, because they contain the same number of the same LED chips, just in different colors. The white LEDs are on the same pins in the bulb harness as the smaller filament in the incandescent lamp, and the amber LEDs are on the same pins as the larger filament.
They may do something clever where all LEDs are on the same circuit, but one color is wired in the opposite polarity as the other, and since LEDs only light up when powered in the correct polarity, only one will light up at once, but the operating principle is the same.
This is also how the drop-in brake LEDs work, because your brake/tail lights are wired exactly the same, pretty much. I think it might power both filaments for brakes, but again the principle is the same. The only difference for the LEDs is one circuit is wired to light up half the LEDs on the bulb, the other lights all of them.
Basically, there are two circuits in the vehicle that go to the turn signal harness. 4 contacts on the bulb and two filaments inside the bulb, one is a low (15W?) draw and one is a high (30W?) draw. When parking lamps are on, the BCM grounds the low circuit, closing it and lighting up the smaller filament for dim amber lights. When the signal is flashing, it repeatedly grounds the other circuit, causing that circuit to close and the larger filament to glow much brighter. As far as I know there is no situation where they are both powered.
Switchback LEDs take advantage of this by having two separate circuits in them with two sets of LEDs. They are the same brightness, usually, because they contain the same number of the same LED chips, just in different colors. The white LEDs are on the same pins in the bulb harness as the smaller filament in the incandescent lamp, and the amber LEDs are on the same pins as the larger filament.
They may do something clever where all LEDs are on the same circuit, but one color is wired in the opposite polarity as the other, and since LEDs only light up when powered in the correct polarity, only one will light up at once, but the operating principle is the same.
This is also how the drop-in brake LEDs work, because your brake/tail lights are wired exactly the same, pretty much. I think it might power both filaments for brakes, but again the principle is the same. The only difference for the LEDs is one circuit is wired to light up half the LEDs on the bulb, the other lights all of them.
old codger
Well-Known Member
I just installed led bulbs in front turn lights. I eleiminated the hyper flash in forscan but the passenger bulb is still hyperflashing though the drivers side is not. whasup??
Axle Folly
Member
A bit tardy on the reply OC, but I was reading just today that some flasher relays need a load to cycle. So, if you defeated the hyperflash electronically in Forscan, you may still need resistors for the mechanics of the flasher relay to function.
Dewey: I looked into how the stock bulbs are wired as I'm in the home stretch of getting my amber turn signals put together. I put a test light on my brake/turn socket over the weekend. What I saw was that both filaments are energized whenever the bright side is activated. So, not knowing if the switchback LED is going to be looking for power on both legs when I'm in turn signal mode, I plan to have diodes on hand that I can splice in to energize the white side of the switchback LED without feeding the reverse light on the other side of the vehicle if need be. I will certainly let everyone know how it turns out.
Dewey: I looked into how the stock bulbs are wired as I'm in the home stretch of getting my amber turn signals put together. I put a test light on my brake/turn socket over the weekend. What I saw was that both filaments are energized whenever the bright side is activated. So, not knowing if the switchback LED is going to be looking for power on both legs when I'm in turn signal mode, I plan to have diodes on hand that I can splice in to energize the white side of the switchback LED without feeding the reverse light on the other side of the vehicle if need be. I will certainly let everyone know how it turns out.
cdahlen
Well-Known Member
I have a 2011, where are good locations to mount the resistors?
gixer2000
Retrofit or Bust
Use forscan to turn off bulb out warning for the rear and put the resistors behind the headlight for the front. Make sure you mount them to the body of the car to dissipate heat
Fred Moore
Member
2017 Expedition King Ranch:
Please help me understand what you mean by the Sylvania 3157R will not work.
I installed them and with the exception of hyperflash, they seem to work fine--very bright. Alas, I reverted back to original bulbs because even with resistors installed and all connections metered for continuity, I still have a bad case of hyperflash--drives me nuts. The resistors are mounted with 2 self-taping screws into sheet metal.
I have not attempted any alterations via FORScan as I don't have the connective hardware.
One question: Do I have to change out & add resistors to the front signals to effect this change?
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