A couple days ago, I went to make a right turn and when I went to signal, the arrow started flashing and clicking extremely fast so I knew the light was out.

A machine at Walmart told me the light guide code was 3157, so I bought 3157, when I went to change the bulb, the actual bulb in the socket was a 3156. The 3157 didn't work. So I bought a package of 3156, they didn't work either. The bulb in the drivers side was completely different than the passengers side. The bulb that died had one connector wire on each side, the one in the drivers side had two on each side.

When I tried to plug the working bulb from the drivers side into the socket on the right, it didn't fit.

I'm not sure exactly what's going on with the lights, I've never had this type of problem before.

All of the lights with exception of the right rear turn signal are working, the interior lights and dash lights are working fine as well.

What could the problem be?

I have a 2004 2.3L XLT Single Cab.

 

To the 27 that viewed but said nothing, not to worry, I figured it out. I'm not sure how it happened, but the drivers side tail lights take 3156, the passengers side tail lights take 3157.

 

Too bad you worked it out because I was just about to tell you how to fix it… lol.

Aren't the 3156 and the 3157 two different bulbs ?
The 3156 is a single filament and the 3157 is a two filament, similar bulbs/sockets, two different purposes.

What taillights do you have, tri-segmented (separate brake/parking, directionals and backup) or two sections (brake/parking/directionals and backup) ?

From what you are saying you have the two segment tail lights, and if I am thinking correctly the 3157 WILL work in the 3156 socket.

Check your owners manual or on the web and see what your truck should have and balance out the bulbs, no biggy if they work but it sounds funny.

 

x2. Based on your avatar, you have an 04+ truck with a two section taillight. Your taillights will take 3157 bulbs which are dual filament. A 3156, single filament bulb, will not work the running light and brake/turn since it cannot get brighter and dimmer since it only has one filament. a 3167 and 3156 bulb will fit in the same socket.

 

yeah if you have a 3156 in there your blinker still wont work lol. they're both 3157

 

Uh... I already fixed the problem.

My turn signal light stopped flashing on the passengers taillight.

I didn't have the guide book and the little machine at Walmart was broken, so I took off the drivers side taillight and it had a 3156. So I bought a pack of 3156 bulbs and went to fix it. Didn't work.

So I took the bulb from the drivers side taillight and tried to plug it into the passengers side, didn't work.

I thought that maybe the socket or wiring was bad, I finally saw it listed that my year truck (2004) took 3157, so I bought it and it worked for the passengers side taillight, I wanted to replace both at the same time, so I put a 3157 into the drivers side taillight, didn't work.

So, I figure someone at the factory must have screwed up, because the sockets are different.

Oh, and yeah, it only has the two sections, tail/brake/turnsignal, and the reverse light.

 

We know !

The two sectioned tails need the 3157 as stated, but you have a 3157 and a 3156… ?
You said they are working properly now ?
If so all well and good but wondering just how both tails are working with different bulbs.
Funny.