Tonight I had a friend over to unsolder the bulbs from the clear light bulb interface of my brake and turn signal spots. Once I replaced the brake/parking 1157 bulb with a LED version the bulb stayed lit like it was getting constant power. Sure enough it had a constant feed.

What I need to know is, has anyone else run into this and how do I go about making them not be on all the time?

 

This sounds familiar to a problem mentioned on the Light that boot! (LED trunk light MOD) thread. Something about a resistor across the incandescant terminals. You might be charting new territory here.

 

I have this, but it is not ALWAYS on (though on for a while). It is the fact that the LED's take SOOOOO little power in comparison to non-LED bulbs so the lights are faintly on b/c of the power being in the line. It is not draining the battery or anything, it is just using the excess power. (That is if you are having the same issue)

Oddly, yesterday I was out with some other mini friends and when someone else unlocked their doors, my LED brake lights went on faintly for a second or two - as if they took the electricty out of the air - it surprised us.

 

Its the fact that you have the modded OEM lights. They are tacked for a reason......to ground it im guessin'. I have the ebay one's on mine now w/LED's. Have never had any problems w/stray voltage.....although I know it does happen. I also have the OEM clears too. But, I haven't needed to put those on yet. You should have to tack the LED's too cause the OEM one's are wired differently from what Im told. Did this make sense.

 

I'm the friend that helped do this. The "stray" voltage is a solid 9.8 volts between the #1 pin and ground. I don't know of any reason to have voltage there all the time.

Steve

 

I know I've seen several mentions of having to regulate the voltage when you switch to LED bulbs - the car is designed to warn you of a blown turn-signal by causing the light to turn on and off much more rapidly. I'd ask this question in the "Electrical MODs" forum - thre are lots of knowlegable electrical guys that post and read in there.

Bottom line is that yeah, this DOES sound exactly like the issue we found with LED boot lights, namely that a constant, low-voltage current does seem to run through some of the circuits (this is true of the OEM boot lamp anyway and it sounds like it's true of the tail lights as well). In the case of the LED boot lights, a resistor was installed across the connection to turn that low-level constant current into heat via a resistor, and it sounds like you'll need to do that here as well. I'm not sure how you'd calculate what resistor you'll need though - sorry.

 

Thanks!

 

The big question I have is why would there be voltage on the taillight circuit only. It is NOT at turnsignal, brake or fog. Just on the running light. It is also not on the front running lights.

I talked to a friend who thought that voltage was a testing voltage for burnt bulbs. Maybe. But that voltage is usaully lower, 5volts. And again why the running lights not the brake or anywhere else?

The mystery continues.

Mark, it maybe time to pick Dan's or Flow's Brains.

Steve

 

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<speculate> These minis and bmws use solid-state lighting controls, not switches, (they dim and gradually increase and such). Without seeing the actually circuitry it is difficult to know what residual voltages/impedances are present in the bulb circuits in the off state.</speculate>

 

You guys want another theory?

In my research into how the BC! module works, it's innards and the type of driver IC used to control power to the lights (to make sure that brake light mods wont totally overpower the chips, which it doesnt), one of the functions available using these drivers is a 'bulb test'. Bulb test passes a small current through the filaments to test for continuity. This current, only a few milliamperes, is not enough to light a normal incandescent lamp. If the lamp were to burn out, there would be no current flow. This condition can then be used if desired to return a warning that a lamp has burned out. This is not done in the MINI. The bulb test current is enough to make LED lamps glow faintly due to an LED's inherent efficiency (an LED can produce a visible light at a tiny fraction of the current used full brightness). As it stands, LED lights used in the MINI will continue to glow for a period of time after everything is turned off until the BC1 module along with other subsystems in the car go to 'sleep', since nothing is really ever 'off' in the traditional sense.

 

This is the best possible solution yet. I referred to something like this either earlier on this thread or the one I started in the electrical forum. There is 9.8vdc but very little current(amps). I didn't know if Mini used something like that. Usually the voltage is lower like 5vdc. strange tho' that "test" voltage is only in the running light not turn or brake light system.

Also I wanted to restate that the voltage reading was at the plug between the #1 pin and return (ground) pin so the solder has nothing to do with the voltage going thru the wires .I do agree the bulbs should be soldered when replaced as not to have an open circuit.

Steve