LED Tail Light Conversion

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Apr 9, 2019
Trying to swap to LED tail light bulbs in my 78’, purchased the right one in pick below hoping to make the swap. Original is on the left. Any leads on making the change? I’m sure it’s on the Forum somewhere.....
I believe you need to change out the whole assembly, and add wiring. Do a search on here, there are a bunch of questions about this process.
Have you tried just putting it in? Mine look like that too, but they work.
I used bayonet style for the markers but went with a sealed unit for the tail lights and front turns on my 70 FJ40 .
I felt that the sealed units gave better lighting and would be less maintenance from dirt and water that might be encountered while four wheeling.
Yours being a 78 probably has the rectangle type light and a sealed unit that fits might be hard to find.
I made my own for the fronts turns.
On my X19 I used the bayonet 1156 and 1157 replacements for the tail lights and they work fine.
As always make sure the grounds are clean
You may need to get a special blinker so the turn signals work.
When I did my X19 I left the incandescent bulb in the dash and that was enough to make the stock flasher work although the flash was hyper at about 140 flashes per minute.
DOT specs are between 60 to 160 flashes per minute so I am with in parameters and for such a little car I like the extra attention.
On my Toy I used the LED flasher and it flashes normally.
I did try, the bulb will press in, but the two ears on the side wil not twist and lock.
Was hoping to avoid changing the entire unit, but may be unavoidable, was hoping I had missed something. LED Bulbs are Superbright 1157, at this point I haven’t had a chance to actually check if they work. Will try again..
the led looks like an 1157 bulb but the original one looks like an 1156. are you sure it’s the right bulb design. posts are off set on the 1157
@mtn biker

What Trailer Lights did you use ?

the led looks like an 1157 bulb but the original one looks like an 1156. are you sure it’s the right bulb design. posts are off set on the 1157
This. The old incandescent bulb (1156) on the left has one contact on the bottom because it has one filament inside. The LED on the right is a replacement for an 1157 bulb that has two filaments inside (usually a marker/tail light AND a blinking signal light or turn signal light), and two contacts on the bottom of the bulb. If you look inside the receptacle in the light assembly into which you are attempting to plug these, you'll see either one or two corresponding contacts. They need to match. Look for the numbers on the base of the old bulb. They are usually stamped in there somewhere, or printed on the metal portion.

If you look at the little metal bits sticking out from the side of the main, metal sleeve, you'll notice that one has two of those tabs ~180° apart, but along the same distance up the sleeve. Not sure that makes sense, but compare the two and you'll see what I mean. The other will probably have two little tabs/posts sticking out 180° apart, but at different heights up from the bottom of the bulb. Those tabs slide down into a little keyed slot on the receptacle and when you turn the bulb, they lock in place. If you're cramming the wrong bulb in, it'll have the same diameter bulb base, but you'll really have to force it past those little tabs and it just doesn't feel right.

Once you know what numbers you need to replace, go to SuperBrightLEDs.com and look for replacements. The on/off lights are easy: side markers, back-up lights, tail lights, license plate lights, etc. The flashing lights are a little trickier, as you have to mess with the flasher module to get them to work right. I replaced all my non-blinking lights with LEDs and it was a huge improvement. Just be careful to use the actual bulbs you have as reference, not just the SuperBright guide. I found a few lights (mostly in the dash cluster) that weren't listed correctly.
Yes the superbright site has 1157 for flasher instead of 1156 which is incorrect. Ask me how I know. :( They did a return and exchange but sounds like they didn’t change their guide.

Consider getting @Coolerman ’s Led flasher module it is plug and play and works perfectly with the led flashing bulbs. Installing in stock location is biggest issue. It’s tight in there. Not sure if compatible with your 78 mine is a 74.

FYI I got these back in 2015 for the non-flashing rear light don’t know if they still exist:

1157-R24-WV 1157 Red 100 Degree
1156-W24-WV 1156 Cool White 100 Degree

And these more recently:


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