Automotive Converting from two wire tail lights to three wire.

corneileous

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My soon to be stepson has a 94 S10 pickup that he’s trying to get ready to go before he gets his license and one of the projects that he’s wanting to do is install some aftermarket LED tail lights that have separate turn signals from the brake lights but the problem is, I’m pretty sure his factory original tail lights are the style where the brake lights, marker lights and turn signals are all in one lightbulb. I know they make a converter device that’s primarily intended for towing a car with a tow bar behind an RV that allows you to properly control the tail lights if the car being towed is a three wire system and the motorhome is only a two wire system but what’s the easiest way to separate the brake light from the turn signal light if you’re just simply wanting to change your tail lights from a single bulb to two bulb?
 

Alaric Darconville

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My soon to be stepson has a 94 S10 pickup that he’s trying to get ready to go before he gets his license and one of the projects that he’s wanting to do is install some aftermarket LED tail lights that have separate turn signals from the brake lights but the problem is
It is fairly straightforward to use a trailer light module to separate the stop and turn functions, but before spending the money, time, and effort to do this, what aftermarket LED taillamps is he installing? 99% of them are absolute junk.
 

corneileous

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I’m not really sure, he showed me a screenshot of what he was looking at but being that it looks like those little S10’s only had a two wire set up where the brake light, rear marker light and turn signal is all on the same light bulb, I don’t think any aftermarket company makes any LED tail lights where the turn signal is separate and on its own circuit so now I think he’s just wanting regular aftermarket LED tail lights and somehow adding an amber turn signal somewhere but what module are you talking about? Does anybody even make one of those modules that you’d have to buy two of, for each tail light? I guess it wouldn’t matter, the type I talked about in my opening post because would work if that’s all there was, it wouldn’t be a hard thing to run two wires from one tail light to the other and just not use the factory brake light/turn signal wire for that tail light.

But yeah, I’m pretty sure there’s some bad brands out there for aftermarket LED tail lights and I wish I had more experience with them to know which ones are good which ones are bad but I had a set of Anzo LED tail lights that were pretty nice but, I ended up selling the truck less than a year after I put them on.

He did mention however that if taking apart a set of LED tail lights was gonna be that difficult of a job that he’d be fine with like maybe a clear lens set of like the old-school euro style tail lights and just using LED bulbs in place of the incandescent ones.
 

RHS-113

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Just a suggestion: I think the brazilian Chevy S10 had seperate amber rear turn signals, with clear and amber lens versions. I also found ebay listings for the amber and clear lens versions, but I'm not completely certain if they're genuine GM parts, or how much modification they would need to work properly on your 94 S10. The mods are probably more knowledgeable about whether or not swapping to (hopefully) genuine GM brazil taillamps is actually a safety improvement.
 
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corneileous

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Just a suggestion: I think the brazilian Chevy S10 had seperate amber rear turn signals, with clear and amber lens versions. I also found ebay listings for the amber and clear lens versions, but I'm not completely certain if they're genuine GM parts, or how much modification they would need to work properly on your 94 S10. The mods are probably more knowledgeable about whether or not swapping to (hopefully) genuine GM brazil taillamps is actually a safety improvement.
Thank you for finding that.
 

turbodog

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Just a suggestion: I think the brazilian Chevy S10 had seperate amber rear turn signals, with clear and amber lens versions. I also found ebay listings for the amber and clear lens versions, but I'm not completely certain if they're genuine GM parts, or how much modification they would need to work properly on your 94 S10. The mods are probably more knowledgeable about whether or not swapping to (hopefully) genuine GM brazil taillamps is actually a safety improvement.

I'm running an overseas import light for my truck. Came with amber turns instead of red. Does not help his wiring issue, but it's a factory-original source for the light assembly itself.

Several european countries mandate amber turn lights.
 

corneileous

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I'm running an overseas import light for my truck. Came with amber turns instead of red. Does not help his wiring issue, but it's a factory-original source for the light assembly itself.

Several european countries mandate amber turn lights.
So what did you do in your situation to make those tail lights work on your truck being that I’m assuming your truck was set up to where the left turn/brake light is in one wire and the right turn/brake light is it just one wire?
 

turbodog

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So what did you do in your situation to make those tail lights work on your truck being that I’m assuming your truck was set up to where the left turn/brake light is in one wire and the right turn/brake light is it just one wire?

No. My truck was dual bulbs... just red lenses for both. I got a european spec assembly.... bolted right in, and now I have amber.

I'm simply commenting that yes, overseas is a good source for the light assembly itself, made by the OEM and not aftermarket.

Like an earlier person said, a trailer adapter might be a good source for the electronics needed to split out 2 wire 1 bulb into 3 wire 2 bulb. They are rugged and waterproof... hoppy is a brand I've used in the past. Some of the better ones include waterproof plugs so it goes right into truck wiring harness w/o cutting/splicing/etc.
 

corneileous

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No. My truck was dual bulbs... just red lenses for both. I got a european spec assembly.... bolted right in, and now I have amber.

I'm simply commenting that yes, overseas is a good source for the light assembly itself, made by the OEM and not aftermarket.

Like an earlier person said, a trailer adapter might be a good source for the electronics needed to split out 2 wire 1 bulb into 3 wire 2 bulb. They are rugged and waterproof... hoppy is a brand I've used in the past. Some of the better ones include waterproof plugs so it goes right into truck wiring harness w/o cutting/splicing/etc.
So your truck was already wired for separate turn signals from your brake lights?

But yeah, I think you’re right, that trailer adapter is probably what he’s gonna have to have.
 

RHS-113

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So your truck was already wired for separate turn signals from your brake lights?

But yeah, I think you’re right, that trailer adapter is probably what he’s gonna have to have.
I also found this picture, which gives you an idea of how someone else with a Chevy S10 managed to wire the brazilian taillamps. Maybe the mods or Daniel Stern will be able to tell you more about things like the safety performance of the brazilian taillamps and whether or not they use different bulbs than the US market S10. Daniel Stern could possibly even help you source genuine GM brazil S10 taillights. And again, I can't verify if the ebay listings I found are for genuine GM parts, so just be advised that they may be aftermarket.
 
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-Virgil-

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Alaric is right; virtually all of the aftermarket "upgrade" lights are in fact a serious downgrade in terms of safety and legality. You're going to want to exercise parental authority and say N-O on this; he either needs to stay with the stock lamps (with correct, specified-type bulbs) or install legitimate alternative taillights such as the factory export-type units with amber (not clear) turn signal compartments. Those linked auctions appear to be for appropriate lamps, but they also appear to not include the bulb sockets. This requires a lot of care and caution, because there are many sockets that will physically fit and click into place, but they are not all functionally the same...they hold the bulb at a variety of different positions not only rotationally but also axially, that is the length distance from the back of the socket to the filament. The filaments have to be positioned correctly for the reflector and lens, or else you don't get an appropriate, safe amount and distribution of light even though the lamp appears to light up.

Most trailer converters are intended to go the other direction (a trailer with combination stop-turn lights pulled by a vehicle with separate stop lights and turn signals), and most of them are half-baked and unreliable; they do a partway job for light-duty, occasional usage, but many of them can't hold up to day-in/day-out usage, and many of them create operational problems of their own...such as causing the rear turn signals to alternate with the front ones when the driver is stepping on the brake, and making random problems when the hazard flashers are in use. You can get a purpose-made control module out of Europe for what you want to do, like this one or this one. (all of Europe, along with pretty much the entire rest of the world, requires amber rear turn signals, not just some countries here and there, hence why there's a market for modules like this...to cater for the private importation of US cars). There is also this US-made module, which is a lot less expensive than the European modules. I have no experience with it, so I can't vouch for it. On one hand, the maker has a reputation for catering to the "car lights are fashion accessories" crowd. On the other hand, they didn't set off any alarm bells or red flags in response to my fairly detailed questions about the function of this module. Maybe the strategy would be to buy it, give it a thorough test in all conditions (both turn directions and the hazard flashers, with and without the taillights; with and without the brake lights), and if it fails to function correctly under any condition, send it back.

Also keep in mind that while installing the export tail lights gets you amber, separate turn signals, which is good for safety (see exposé), it also deletes the side marker light and reflector functions, which are required in the US and Canada and which are effective crash-prevention devices. There is probably enough wrap-around visibility of the tail light to provide reasonably adequate side visibility of the rear of the truck, even though it won't extend as far forward as with proper side marker lights. You can make a judgment call on that, but the side reflector function definitely needs to be provided. It's not hard; you can just apply these (don't try to make do with just "any old" red reflector). Or you can install integral side marker light/reflector units, such as these.

Sonny boy also should pay some attention to the headlamps on that truck, and pop should see that he does so carefully, appropriately, and in a manner that will (actually, really) improve safety rather than worsening it. That means no aftermarket headlight-shaped toys, no "LED bulbs", no "HID kits", no blue bulbs, etc.
 
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corneileous

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Alaric is right; virtually all of the aftermarket "upgrade" lights are in fact a serious downgrade in terms of safety and legality. You're going to want to exercise parental authority and say N-O on this; he either needs to stay with the stock lamps (with correct, specified-type bulbs) or install legitimate alternative taillights such as the factory export-type units with amber (not clear) turn signal compartments. Those linked auctions appear to be for appropriate lamps, but they also appear to not include the bulb sockets. This requires a lot of care and caution, because there are many sockets that will physically fit and click into place, but they are not all functionally the same...they hold the bulb at a variety of different positions not only rotationally but also axially, that is the length distance from the back of the socket to the filament. The filaments have to be positioned correctly for the reflector and lens, or else you don't get an appropriate, safe amount and distribution of light even though the lamp appears to light up.

Most trailer converters are intended to go the other direction (a trailer with combination stop-turn lights pulled by a vehicle with separate stop lights and turn signals), and most of them are half-baked and unreliable; they do a partway job for light-duty, occasional usage, but many of them can't hold up to day-in/day-out usage, and many of them create operational problems of their own...such as causing the rear turn signals to alternate with the front ones when the driver is stepping on the brake, and making random problems when the hazard flashers are in use. You can get a purpose-made control module out of Europe for what you want to do, like this one or this one. (all of Europe, along with pretty much the entire rest of the world, requires amber rear turn signals, not just some countries here and there, hence why there's a market for modules like this...to cater for the private importation of US cars). There is also this US-made module, which is a lot less expensive than the European modules. I have no experience with it, so I can't vouch for it. On one hand, the maker has a reputation for catering to the "car lights are fashion accessories" crowd. On the other hand, they didn't set off any alarm bells or red flags in response to my fairly detailed questions about the function of this module. Maybe the strategy would be to buy it, give it a thorough test in all conditions (both turn directions and the hazard flashers, with and without the taillights; with and without the brake lights), and if it fails to function correctly under any condition, send it back.

Also keep in mind that while installing the export tail lights gets you amber, separate turn signals, which is good for safety (see exposé), it also deletes the side marker light and reflector functions, which are required in the US and Canada and which are effective crash-prevention devices. There is probably enough wrap-around visibility of the tail light to provide reasonably adequate side visibility of the rear of the truck, even though it won't extend as far forward as with proper side marker lights. You can make a judgment call on that, but the side reflector function definitely needs to be provided. It's not hard; you can just apply these (don't try to make do with just "any old" red reflector). Or you can install integral side marker light/reflector units, such as these.

Sonny boy also should pay some attention to the headlamps on that truck, and pop should see that he does so carefully, appropriately, and in a manner that will (actually, really) improve safety rather than worsening it. That means no aftermarket headlight-shaped toys, no "LED bulbs", no "HID kits", no blue bulbs, etc.
I'm not his dad so I'm not going to say what he can and can't use. But yeah, I'll send an email to that place that sells the converter you linked that's made in the US to see if that just works for one tail light- meaning he'd have to buy two or if it works like the typical RV one like this. Which, he could use the one I linked in the previous sentence, people said in the Q&A section that it is waterproof.
 

corneileous

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@-Virgil-

Well, I just got off the phone with the people that sell that Digi-tails module thing and I’m not so sure if that’s gonna work because the guy said that it has to be mounted inside the cab and well, I guess it could work but that be an awful lotta new wiring that would have to be ran just to hook it all up so I don’t know, we’re probably just gonna have to settle on one of those ones that I was talking about earlier, the one that a typical RV’er would buy if he was toting along a car that had tail lights with separate turn signals and his motor home had the combined brake lights and turn signals.
 

RHS-113

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corneileous

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I’m not really sure at this point what he’s
@corneileous So I've done more digging and found that if this mercado livre ad is correct, the brake/tail lamp uses a P25/2 (P21/5W) while the turn signal uses a P25/1 (P21W). I suspect it might take more time, money, and effort then what you or your son in law are willing to go through to get export taillamps, find P21W and P21/5W bulb sockets that work correctly, and get it all wired up correctly to the truck.
I’m not really sure at this point what he’s wanting to do about tail lights but I did find out that the module @-Virgil- recommended from Digi-Tails will work in his application. I called the number on the site and talked to one guy but he didn’t really know so then he took my number and had the engineer call me and he said it can be mounted anywhere, that it’s completely waterproof and that it was pretty much designed for people who are doing custom lighting who like, for example, want to convert their vehicles from a two-wire to a three-wire.
 

RHS-113

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I’m not really sure at this point what he’s

I’m not really sure at this point what he’s wanting to do about tail lights but I did find out that the module @-Virgil- recommended from Digi-Tails will work in his application. I called the number on the site and talked to one guy but he didn’t really know so then he took my number and had the engineer call me and he said it can be mounted anywhere, that it’s completely waterproof and that it was pretty much designed for people who are doing custom lighting who like, for example, want to convert their vehicles from a two-wire to a three-wire.
Sorry, I wasn't thinking too hard when I wrote that. I just thought it's possible it might take more effort then what you guys are willing to do because of the bulb holders. Like what Virgil said, there are lots of different bulb holders out there that will lock into place but will not put the filaments in the right place. I can't imagine finding the right P21W and P21/5W bulb holders for the export taillamps will be easy. There's also concerns about sourcing genuine taillamps. There are for sure genuine export taillamps for sale on mercado livre brazil, but I can't imagine getting those will be easy. Looks like you'll get the wiring part figured out eventually.

If you're at all interested, I found a bunch of amber lens and clear lens S10 export lamps for sale on mercado livre brazil, made by Arteb and Cibie: Clear, Clear, Clear, Clear, Clear, Amber Cibie, Amber Cibie, Amber, Amber, Amber.
 
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-Virgil-

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The sockets shouldn't actually be all that difficult; it's likely one or another of the widely-available GM sockets (for each type of bulb) will work correctly. It's not even all that difficult to suss out whether you've got the right ones or not, using trial and error with a workbench, a power supply, and a nearby wall. The wrong socket will result in a bright spot of light visible in the lamp, but a diffuse mess of bright streaks and dark bands on the wall. The right socket will result in the whole apparent area of the lamp lit up and a coherent, bright patch of light, usually round or oval or rectangular, on the wall.

Cibie and Arteb are both OE suppliers.
 

turbodog

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If you're at all interested, I found a bunch of amber lens and clear lens S10 export lamps for sale on mercado livre brazil, made by Arteb and Cibie: Clear, Clear, Clear, Clear, Clear, Amber Cibie, Amber Cibie, Amber, Amber, Amber. edit: fixed a broken link

IIRC, Arteb is where I got my amber units for my 2013 ridgeline back in the day. The sockets were about .5/100" looser than factory, but have made it 9 years w/o problems.
 
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