Hey guys,

I'm having this issue with these bulbs: PAIR OF (2) 1157 39 LED 1210 SMD CAR BULBS - RED on eBay.ca (item 190482652005 end time 21-Apr-11 14:33:02 EDT)

The bulbs installed fine into the socket. Without any lights being turned on, when I hit the brakes they light up as well as the 3rd brake light. When I turn on the lights the bulbs light up but so does the 3rd brake light. When I hit the brakes with the lights turned on the LED bulbs and the 3rd brake light do go brighter. I'm wondering if there is something I can do to fix this?

Cheers,

 

Anybody? Somebody? Will some sort of resistor fix this issue?

 

A coupla questions:

If you replace the LED's with the stock bulbs does everything work as it should? Is your bulb out indicator on?

If so, you need to get canbus bulbs or add resistors. Another way to cheat the system is to splice in another small incandescent bulb to each taillight, something with a 5w draw.

 

Bluecoupe,

Thanks for the reply.

With stock bulbs in everything operates as it should with no bulb out indicator.

I was thinking I'd rather buy resistors than send back these LED bulbs and trying to find canbus versions. How can I figure out what resistors to get, and can I get them at local electronic stores or just online?

Thanks,

 

Keep me posted if you find a solution, as I have 20LED bulbs for my brakes that do the same thing, I could not figure it out, and did nto spend much time trying, hopefully you will be more ingenious than I was

 

I have my fingers crossed Bluecoupe will come back and let us know how to figure out what resistors we need to make this work.

 

What color LED's are you using for the Brake lights? Red or white?
I've wanted to do this but found an article claiming the RED don't shine through the RED plastic properly?

Let me know

 

Sorry can't help with the resistors, I've never used them, I just commented on what I had read on the forum. I put LED's in my back up lights and had the same problem. With the bulb out indicator system there's always some voltage present, not enough to light an incandescent bulb but enough to light a LED with the ignition in the run position. (this is the reason your CHMSL stayed on, it's LED). So I left one LED bulb in one back up light and one stock bulb in the other back up light and the LED went out with the ignition in the run position. When I put the car in reverse both lit up but the bulb out indicator came on. So I wired in a small 5w bulb to each backup light and put the LEDs back in both back up lights. Now the back up lights stay off with the ignition in the run position, go on with the car in reverse and the bulb out indicator light stays off. The 5w bulbs light up with the car in reverse but you don't see them tucked away behind the trunk panels. Same concept would apply the each one of your running lights. For the brake lights, I'd go with a brake light pigtail from the wreckers or any auto supply store and then paint the bulb black.

 

My guess is that if you turn the bulb around in the socket it will work. But if they are only able to fit in the socket one way you are screwed. (or bayoneted )
My guess is that the bulb feeds power to the 3rd brake light as it is powered by the wrong circuit.
Maybe a diode is required or an existing one has failed.
I'll check the circuit to see if that is possible.

 

I dont' know if this helps or not or if I just dont really understand the problem... but when one of my brake lights was out I purchased the wrong bulbs, it only had a single filament and the same thing was happening to me.. the 3rd brake light was always on and my brake light wouldn't really get any brighter when I hit the brakes..

The real bulbs are dual filament, the second filament is a lot brighter than the first which is when the brakes are pressed...

With the LEDs, i'm sure they are all the same. They are probably messing up the circuit just like my wrong bulb did.... i'm not sure how you would fix this, since I don't know if they make dual leds??? if that makes sense

 

For the brake lights, I would install the resistors that are normally used to fix turn signal speed.
If the bulb out indicator lights with the tail lights, I think you need resistors for them also but these may need higher resistance then the brake lights.

I put leds in my Miata turn signals because I like the instant on-off look but am concerned that they are not as bright as filament bulbs. What do the leds in the tail and brake lights look like?

 

I'll take one more stab at this, the picture shown on ebay has two terminals that are for two circuits in the bulb, I'd guess two sides for rear light and four sides for rear and brake lights. Does your bulb have two terminals? I am surprised that a single filament bulb even lit up, as they have a center terminal I thought. A single filament would not get any brighter, as 12 volts is still 12 volts even if the center terminal touched both contacts. For the same reason I cannot see the third brake light getting brighter.
I would suggest putting the correct bulbs in and see what happens, this would show if there is a problem with the circuit and lay the cause of the problem on the LED's if there is no problem.

 

I currently have the old filament bulbs back in and everything is operating exactly how it should. The base of both the filament bulbs and the LED bulbs look the same, as you said two terminals (metal pieces) on the bottom of each bulb. With that info, would you say a resistor is the right fix? To trick the car into thinking the bulbs are getting the same amount of resistance as the filament bulb does anyone know what resistor would be necessary to splice in?

 

OK, have you tested the LED bulbs by applying power to each terminal on its base?
Power to one terminal and the side of the bulb should light up one half of the bulb and the other half should light up with power to the other terminal.
Does all of the LED light up with power only to one terminal and the side?
Can the LED's fit both ways in the socket?

 

When the bulbs are in the sockets they function correctly *when headlights are switched off*. When I turn on the headlights the LED's light up, then when the brake is depressed they light up brighter. The problem is that the third brake light comes on when the headlights are turned on, and it flashes brighter as well when the brakes are depressed. The bulbs go into the socket exactly like the filament bulb, they seat in by being pushed in and turned clockwise.

 

That's exactly what I understood your problem to be. My solution may not be perfect, but it will work!

 

As a last resort, I will! If the 5W bulb would work, does that mean a 5w resistor would also work? I'm electrically illiterate so I'm flying blind here...