Convert non CK 3157 LED bulbs to 3157CK

I was interested in changing my signal bulbs to LED, and perhaps use swtchback LEDs in front, and learned that tacomas need 3157CK bulbs, which costs quite a bit more than the non CK bulbs.

switching all 4 signal lights costs quite a bit, (got quoted $182 ). I figure I can do better. So the first thing I did is to convert a regular 3157 bulb to 3157CK as follows:

First, get your 3157 bulb. I got these switchback LED bulb pair for $7.29 shipped from an ebay seller in New Jersey.


next, straighten out the 4 pins and pull out the LED tower assembly from the socket.





once the LED assembly is out, you can see the ground wires are tied together, and one wire for white (dim) and one wire for amber (bright).

For CK bulbs, the inner pair of wires are the dim, and outer pair of wires are bright, with the two ground wires on one side (one on inner edge and one on outer edge of the side). All you need to do is identify which is white and which is amber, then reposition the wires and push it back out of the socket and bend them again.



you can use a 9v battery or any 12v adapter. remember which wire is amber and which wire is white.





arrange the wires like this
amber--gnd--white--gnd
and insert back into socket. you may need to twist and position the LED assembly so the wires do not get in the way of the socket. It may take a few tries, but you will eventually find the right position. Make sure you do not short any of the wires together (except for the two ground wires).
This is the finished product. The wires may be a tad shorter, but that is ok, the contact is closer to the edge anyway.

Before you plug in to socket, do one last check to make sure white and amber wires are not shorted to anything.


looking at the above picture, the top (outer edge) wire is amber, the lower (inner edge) wire is white. On the other side, the top (inner edge) and bottom (outer edge) are both ground wires.

I had to sand down the left and right edges of the socket a little bit (I used a dremel) since the socket is a wee bit too wide to fit into the light bulb socket. Once I got it in, it works perfectly.

http://youtu.be/eDdtNpvzDCc

My next project is to add DTRL in order to use the switchback for $8.75 (cost of the LED flasher relay). I figure I can convert all 4 signal lights to LED, add DTRL, fix the hyperflash all for around $30 (not bad compared to paying $180+ for something that uses resistors, cutting wires, etc). (imho, using resistors as a workaround to fix the hyperflash is a really bad idea. just because something works does not mean it is proper) Stay tuned for my improved dtrl mod.

This is not rocket science, anyone can do this. I started from zero knowledge to this in a couple weeks. This information is shared freely to the community forum, as I learned quite a bit from scouring through the posts here.

 

I modified the second bulb and it took only a minute.

When you pull out the LED assembly, look at the wires before completely pulling it out and note the locations. Also, remember the orientation of the LED assembly with respect to the base, it will make reinserting a lot easier.

Note the location of the wires as shown in this picture


Then all you need to do is rearrange the wires so it is
amber-ground-white-ground
you are basically switching the position of the two inner wires.

then insert it back into the base in the same orientation as when you pulled it out and then bend the wires. That's it.

 

Subbed

 

I got another pair of regular 3157, amber only. These use 27 5050SMD, which is brighter than the 60smd switchback white/amber LEDs. On the bright connection, all 27 LEDS are on full brightness. That's equivalent to having 81 3528 LEDs used in the 60LED bulb for which only 30 are for white and 30 for amber, so it should be at least twice brighter. The DIM connection simply wires a 33 ohm resistor in series, all 27 LEDs still light up, but dimmer.

with this bulb, the LED assembly is glued to the base using the hot glue gun stuff, so it is relatively easy to pry off with a small flathead screwdriver. This is what it looks like



same as before, all that is needed is switch the two inner wire positions, then when bending the wires, bend the 2 ground wires to the same side of the wedge.

If these work well, I think I'm going to get another pair. They sell on ebay US seller buy it now for $8.99 or best offer. I got it on $8 offer.

 

I also got the 8 pin LED flasher relay and a regular relay I am going to use on my DTRL mod. Also got the add-a-circuit in the mail.



got them all from ebay
Toyota 8 pin LED flasher relay $8.75 (I literally got this in one business day, mailed from NJ on Saturday and got it in CA on Monday. US mail is fast)
relay with socket $5.94
add-a-circuit $1.29


I'll wire these up this weekend. I might wire a truck bed LED strip as well. I got an RGB LED strip with remote control for under $10 from ebay.

 

I don't think the amber 3157s I got are suitable for use in front dtrl/signal because of the way they are wired. if dtrl is on, the turn signal indicator lights on dash and the rear signal may be on since they are all on the same circuit. Besides I tested leaving it on 12v for a minute and it got hot. I also see superbrightled website list these 5050smd bulbs as not suitable for drl. I can see why. I think they are perfect for the rear signal (which is where I intended to use them in the first place) replacement since they will be brighter.

 

Sub'd

 

FWIW, I decided to just keep using the incandescent bulbs on my truck, and just use my fog lights as my DRL.
http://www.tacomaworld.com/forum/technical-chat/324515-my-version-fog-light-anytime-mod.html

Nothing wrong with LED for turn signals, I just prefer the look using incandescent after comparing the two.

I personally like the look of using fog lights as DRL, and not risk melting the turn signal lenses using incandescent bulbs. I use 5k HID, which I think is way better and way brighter than any LED fog or headlights out there.

The information on converting Non-CK to CK above is still good though. And you can save quite a bit by not buying a CK bulb, which I'm pretty sure, the LED bulb sellers are just doing the exact same thing then just doubling or tripling the price or more.

I started a new thread for my bed light install.
http://www.tacomaworld.com/forum/li...ome-light-circuit-lots-pics-wire-routing.html

 

So you are just pairing each inner wire with a ground? If I'm understanding correctly I have sold white leds that look like your first pic let me know if this is correct Thanks

 

That is correct. And I can guarantee you that is exactly what is in the overpriced CK bulb you see sold here and elsewhere.

 

Ok awesome I'll be doing this today or tomorrow whenever the bulbs show up Thanks for the write up and info

 

I tried to convert nothing comes on out a regular led not messed with still no light put the old halogen back in it lights up idk what's going on

 

Subbing to this.

 

Hmm