Led running lights (tail Lights) not working

Sometimes the LED bulb contacts are a few thousands off and not making contact with the bulb sock, you have to fiddle with them a bit.

Alan Merklin posted:

Sometimes the LED bulb contacts are a few thousands off and not making contact with the bulb sock, you have to fiddle with them a bit.

I did fiddle with it no luck. The bulb socket is pretty corroded inside but the old bulb still works?

Unlike incandescent bulbs, LEDs are polarity sensitive - does the socket allow them to be flipped 190 degrees? 

I found when I installed the LED taillight bulbs, that the male end of the bulbs contacts did not reach as the old bulbs did. I had to replace the corroded old spring beneath the contact button plate with a fresh 40 cent spring from the hardware store. A small pain, but worth it for the higher visibility.

Also, the sockets have a shallow and a deep groove to lock the bulb in place which eliminates the ability to flip the polarity without switching the wiring pigtail. 

My bulb sockets are pretty corroded. I have a spare set of tail lights housings. My spare tail lights are designed for 1156 bulbs. So I managed to pull one socket out. Is there a place I can buy 1157 tail light bulb sockets that will fit in the housing?

Safety Jim,

You may be correct about reversing polarity on a twin-filament bulb, but that's not my understanding.  The two connections on the bottom of an 1157 bulb are not positive and ground, they are both positive, each leading to a different filament in the bulb.  The two filaments have different diameter wire, so that the brake light with the heavier wire is brighter than the turn signal.  The bulb is grounded through the case.  That's my understanding, but I may have misread your post above.

You are correct! The only way to change the polarity is to reverse the wires being sure the housing of the socket is connected to a ground. One of the other poster's suggested attempting to reverse the bulb in the socket and that won't work.  I've been through hell and back before realizing the slight difference in the depth of the bulb bases and it simply not reaching the contact.  Also, with the LED's your ohm meter will only read the resistance, (completion of the circuit) in one direction. 

"Also, the sockets have a shallow and a deep groove to lock the bulb in place which eliminates the ability to flip the polarity without switching the wiring pigtail. "

Jim's answer is spot on.  If the bulb has only one filament then the locating pins on the outside of the base are usually at the same height because it doesn't matter which orientation the bulb is in.

The LED, in the other hand, is a semiconductor diode, meaning that it only works (lights up) when attached to the wires (+12 and ground) one way.  Reverse it and nothing happens at all.  However, I would sincerely doubt that anyone on this forum has a car with tail lights wired bass-ackwards so your finding that the contact spring had weakened over time was not a surprise - happened to me, too!

Adding those LED tail light bulbs made a YUGE! difference on my car, too.

"Is there a place I can buy 1157 tail light bulb sockets that will fit in the housing?"

Sure - try a NAPA store.  It'll be best to bring the old socket with you to insure that you get the same OD and depth as they'll surely have several in their catalogs.  Forget the online store - go in and ask to see their "Standard Electrical" or "Echlin Electrical parts" (Echlin would be my first choice) catalogs and start turning pages (Maybe Dorman has them, too).  If I find something close in my catalogs here, I'll flag a part number for you later on.

Can't find my Echlin catalog, but in the Standard "Engine Management" catalog (ENGB-99) they list  a bunch of replacement sockets.  For a double lead the try S-26N, S-32 or S-36N.  All of those fit an 1157 bulb

For the single filament bulb try sockets S-21, S-26N or S-35.  They all fit an 1156 bulb

The single wire pigtail replacement assembly is S-23 or S-57

The double wire replacement pigtail assembly is S-24 or S-51

I doubt that any of those part numbers have changed over time.  There are a bunch of other sockets and pigtails, but some are press-in to slightly larger holes.  THAT's why you should bring along what's in there now to compare.

Good luck!    gn

Gordon Nichols posted:

Can't find my Echlin catalog, but in the Standard "Engine Management" catalog (ENGB-99) they list  a bunch of replacement sockets.  For a double lead the try S-26N, S-32 or S-36N.  All of those fit an 1157 bulb

For the single filament bulb try sockets S-21, S-26N or S-35.  They all fit an 1156 bulb

The single wire pigtail replacement assembly is S-23 or S-57

The double wire replacement pigtail assembly is S-24 or S-51

I doubt that any of those part numbers have changed over time.  There are a bunch of other sockets and pigtails, but some are press-in to slightly larger holes.  THAT's why you should bring along what's in there now to compare.

Good luck!    gn

Gordon thanks for the info. I will look into it on Monday 

JB356SR posted:

Alan Merklin posted:

Sometimes the LED bulb contacts are a few thousands off and not making contact with the bulb sock, you have to fiddle with them a bit.

I did fiddle with it no luck. The bulb socket is pretty corroded inside but the old bulb still works?

@JB356SR  I replaced my filament bulbs (1156 & 1157) with LED bulbs I found at Pep Boys ($20/pkg of 2)

I had same issue as you are having. Filament bulbs work (even with mild corrosion in bulb socket, insert LED, doesn't work.

I found that the LED bulb was slightly shorter (in depth) than the filament bulbs and not making contact with the contacts at bottom of bulb socket.

Refering to your picture pic below, I removed the bulb socket and pushed (or tapped) the bottom of the socket (RED ARROW) just slightly higher into the sleeve (YELLOW ARROW). I put a 13mm socket over the part with the wiring screw (BLUE ARROWS) so I wouldn't damage the screw attachment, then tapped the 13mm socket lightly. 

Inserted LED into socket, VOILA, LED works. (Note: No polarity issues or any or that other complicated stuff). 

Hope you find this simple process helpful! 

P.S. - The LED bulbs are MUCH brighter than filaments and do not generate enough heat to effect or melt lenses. If you can find those LEDs in red, it will be much better than the white LEDs. The red LEDs give a more bright red appearance than a slightly washed out red with the white LEDs (hope that makes sense).

The inside of the socket corrodes over time while the bulb is in there.  The socket’s ceramic contact washer literally gets rusted into place at the depth of the original bulb.  When you replace the original bulb with a new one and that one is just slightly shorter (the MUSBJIM syndrone) the contact washer is still held in place and the spring can’t move it up to the contact on the bulb.

Usually, my fix is NOT to replace the socket, but to push the contact washer, wires and spring out through the top of the socket, then use a small Dremel tool (be careful - the wires are still in the socket) with a light abrasive tip and just buff the rust out of the inside of the socket, thereby releasing the washer to travel a bit farther up the socket bore.  Stretching the spring a bit before putting everything back together wouldn’t hurt, either.

Put some dielctric grease around the base of the bulb to seal it and you’re good to go.

Come to think of it, if you can get to the rear of the light and pull on the wires coming out of the back of the socket (without the bulb in there), you might be able to slip in a Dremel tip, maybe even one of those 1/2” round sanding drums down in there to make a couple of passes and clean it up.  Let the wires pop back up, put in a bulb and Bob’s your uncle.

Did a little research on the NAPA website. Found a bulb socket that might work UNI LS6538. I need to replace the outer bulb socket with a 2 wire 1157. The tail light housing came with two 1156 style of bulb sockets (see photo previous post) so it won’t work.  Don’t know why it was made that way?