None that will work it seems. They burn out really fast due to voltage issues on our DRLs.

 

I ran 3157A in my DRL on my '05. I did the 35w mod, and they looked great. I didn't have any issues with premature burnout. in fact, I liked them a helluva lot better than the regular incandescents. A lot less heat to cook the socket and haze the lenses.

 

35W MOD????? not familiar...

 

3157 Bulbs have 2 Filaments in them. A 27w Filament and an 8w Filament. Normally, the Filaments are used 1 at a time. The 8w will serve as the Running Light and the 27w will serve as the Turn Signal.

By Single Use, I mean it serves as 1 Function ONLY. As in a Chevy Truck, the DRL and Backup Lights use a 3157 Bulb, but only use it for 1 thing. The DRL's only Function as a DRL, they are not on as a Running Light, they are not on as a Turn Signal. The Reverse Light only Functions as a Reverse Light, it is not used as anything else. So with a 3157 Bulb in that Spot, 1 Filament NEVER gets Lit. Why waste a Filament, and only have 27w of Light Output when you can use BOTH Filaments, and have 35w of Light Output!!

Here is what a Standard 3156 Socket looks like. Notice the 2 Ground Tabs, and only 1 Power Tab. This is because a 3156 Bulb only has 1 Filament. But a Dual Filament 3157 Bulb will fit in it's spot 100% fine, but only the 27w Filament will be Lit, the 8w Filament will stay out because there is no Power Tab on the other side of the Plug to make Contact with the Pin on the Bulb.:

Here is the Bottom of a Standard 3157 Bulb. Notice the 4 Pins. 2 are Positive, 2 are Ground.:

What you are going to do is use a Razor Blade and pry up on the Pin that is on the side of the 3157 that is NOT getting Power when it's in the 3156 Plug. You want to pry at the TOP of the Bulb Base. NOT at the Bottom where the Pins come out.

Now wrap that Pin back around to the opposite side of the Bulb Base and join it with the other Pin that IS getting Power. If you do it correct, it will look like this.:

Now just pop the Bulb back into the Plug, put everything back together and you are done. Enjoy 35w of Lighting Power instead of a measly 27w.

To verify it is done correctly, turn on the Light and look to see if BOTH Filaments are now Lighted. If they are, you've done it correctly.

 

very nice explination callie454

 

I'm real good at copy/paste. :HiHi:

 

So you did this with a led bulb too?

 

Yessir.
I did this with incandescent bulbs, but found that the heat put off could scorch the bulb socket and haze the light housing. The cool running LEDs worked perfectly. They still have a relatively short lifespan, but at least GM made it easy to R&R them. I'm not doing it on my '13 because the 07.5+ headlight is such a pita to service. It's easier to remove the transmission than to change a blinker bulb...

 

About the LEDs-
Because they are polarity specific, you'll need to make sure you're bending the proper wire. You'll see what I mean once you dig into it. You'll need to key the truck to "run", apply the e-brake, and put it in gear to power the DRL lights. Then it's just a matter of testing the bulb in the socket to make sure the correct wires have been flipped over. Piece of cake.

 

callie454, what brand bulb did you have the best service life with?

 

I like GP Thunder GP Thunder Official Website Type the brand name into eBay along with the bulb size. Lots of vendors carrying them.

 

Thank you for the writeup...
I looked at Ebay and the GP Thunder 3157 search, too many results. If you are pleased with your choice, can you maybe give a clickable link to ebay site. I prefer a white lamp normal replacement.
My experience with drop in replacement leds have been very mixed. I've paid a lot and been disappointed.

 

I've had good luck with these bulbs and this vendor- GP Thunder 3157 3156 3457 3057 3047 3155 3357 SMD 30 LED Lights Bulbs White | eBay

Might as well pick up a 10 pack of these while you're at it. You can use them in a zillion places- interior, corner markers, etc. Good experiences with the bulbs and vendor - Lot of 10 194 168 2825 W5W T10 5050 SMD 5 LED GP Thunder Light Bulbs Super White | eBay

 

Here's a link for those of you that prefer amber DRLs - Pair GP Thunder 3157 3057 4157 SMD 30 LED Lights Bulb Amber | eBay

Once again, I like the vendor and the bulbs.