LED WARNING!!!

[MisterEd]

Replaced my oem brake/tail bulbs with led 3157s.

Shop where I bought them and package indicated "direct replacement"...

Not true........causes some kind of "electrical feedback" that prevents the cruise control from working....

GMC techs had to assist my dealer in tracking down the problem but after changing the bulbs back to stock, cruise now works fine.

Beware..........

If guns kill people, then forks made Rosie fat.

[MisterEd]

Replaced my oem brake/tail bulbs with led 3157s.

Shop where I bought them and package indicated "direct replacement"...

Not true........causes some kind of "electrical feedback" that prevents the cruise control from working....

GMC techs had to assist my dealer in tracking down the problem but after changing the bulbs back to stock, cruise now works fine.

Beware..........

If guns kill people, then forks made Rosie fat.

[NSXer]

is that why my cruise control sucks gigantic hog balls????

If you like bikes... Check out http://www.usualsuspex.com

[MisterEd]

Mine wouldn't even suck................

If guns kill people, then forks made Rosie fat.

[HappyJack]

Thanks for the heads-up. I was looking at those LEDs just today!

Cheers

[BADRAP]

Ya I postede something about this in the light forum a while back and I ran into something similar. The A/C went out and I had to have the entire head unit for the Climate control stuff replaced... So be careful...

BADRAP
03 H2, Lux, Pewter
03 BMW 525i, Titanium Gray Metallic, Black Leather, Loaded...
H2 Club - Houston Chapter..
badrap@sbcglobal.net

[H2Norcal]

We have been doing some testing with LED replacements for the H2 and have been experiencing the same issues. In our case it was just blowing the fuses. We believe there is a relay build up that is causing the trouble.

We have two high-end LED manufacturers we are checking next. The cheap Taiwan products at your Kragen, Pep Boys and other chain stores all failed. The problem with the high-end guys is they are $50bucks a bulb.

I really don't think any will work. They draw too much power or something.

[GasGuzzler]

I have an answer to this old question.

BTW, the price of the LEDs will not matter.

For the cruise control to work, you will have to add a load resistor across the ground wire(w/ black stripe) and the brake wire and then another resistor across the ground wire and the tail light wire.

The LEDs are consumming too little current. The cruise controller thinks you are constantly applying your brakes. Adding the 6 ohm load resistors will create another 2mA path for the current to flow.

If you want LEDs on your turn signals, you will have to do the same thing.

Check Ebay for the load resistors

[MisterEd]

Appreciate the info!

[sbmike]

Gas Guzzler: I'm confuzled (not unusual, by the way ). After reading your response I was prepared to purchase 4 resistors but I emailed the seller on ebay and got this response back: "We had a customer tell us when replacing stop/tail lights the cruise control does not work on the H2. You only need resistors on the blinker bulbs, one per bulb." (Could the customer be MrEd above?) Anyway, do I need a resistor for each turn signal or a resistor for each turn signal and each tail/stop light? Thanks.

[Dan]

I would get all 4, just to be safe. But that's just me.

[MisterEd]

LEDs in for brake lights, no cruise control...

That's everything I know which isn't very much!!

[Hummer Man]

GAS GUZZLER is right it is feedback through the ground that is causing the issues. At some point the high end bulbs will address this issue and then it will be safe to buy them.
It is a difficult problem to troubleshoot because it is sporadic!

[Boar-Ral]

I picked up my 2005 Hummer H2 on Saturday and have not had a chance to open up the rear brake light enclosure. In my Avalanche, there was enough room to wire in the original brake lights in-line and hide them behind the enclosure. (There was enough room so that they wouldn't overheat.) Since the LEDs draw almost no current, combining them with the original bulbs allowed everything to work perfectly. Just my two cents, though until I check out my H2, I cannot say if it is practical in this instance.

[GasGuzzler]

Hi all,

Heres the scoope.

LEDs on the blinkers are 100% OK if you add the resistors. It will fix the fast blink problem.

If you use LEDS on the brake/tail, your cruise will not work. Adding the resistors will fix the cruise problem but the resistors can get hot specially when the taillights are ON constantly at night. This can be a fire hazzard.

Please stay tuned. I have a few ideas in mind and will try get to them as soon as I have more time.

[sbmike]

Thanks GG. Waiting patiently...... Well? What's the solution? Oh... you meant like days or something... I see that now...

[ChuckE]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by GasGuzzler:
...
Adding the 6 ohm load resistors will create another 2mA path for the current to flow.
<HR></BLOCKQUOTE>

NOT a 2mA load! For your information a 6 ohm load, on a 12v circuit is a 2 amp load.
A 2 Amp load with a 12v supply equals a 24 watt consumption.

Wow, that is why someone later mentioned that the resistor heats up!

While I do not know how much of a load is really required for the proper detection of the brake lights, for the cruise control circuits, I would hazard a guess that a 1 amp, or even just a 0.5 amp load, would suffice.

To acquire a 1 amp load you need a 12 ohm resistor, on the 12v circuit (power draw would then be 12 watts, still fairly warm).
or
To acquire a 0.5 amp load you would need a 24 ohm resistor. That results in a 6 watt draw (warm, but not toasty).

So, whatever resistor you try out, make sure that the resistor can handle the power. By the way, a 5 watt resistor, depending upon composition, is typically about 1 inch long and about a quarter inch thick. So don't think just any resistor will work. Use a resistor that is AT LEAST the power range you need. It is better to have a larger resistor, more power capability, to keep the "to the touch" heat of the resistor down.

[sbmike]

I finally swapped out my turn signal lamps this past weekend and I really like the difference they make. I used the resistors as recommended by the lamp seller and by GasGuzzler. I thought about installing the LEDs on my brake/tail lamps but just for yucks I left one of the turn signals on for a while and GasGuzzler is right on the money about the resistors heating up. Even after a very short time, the resistor was almost too hot to hold in my hand. So I quickly decided to hold off installing them for the moment.

[ChuckE]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by sbmike:
... after a very short time, the resistor was almost too hot to hold in my hand. <HR></BLOCKQUOTE>

Right, resistors can get warm. That is their design. ALL resistors get warm, it is a function of their operation. The energy is dissipated in the from of heat. How much heat is a function of how much voltage is applied the resistance. If the power design of the resistor is exceeded, then the resistor will get dangerously hot, and could possibly burn either itself, or the surrounding material. Large wattage resistors are physically larger, so as the heat is dissipated over a larger surface.

If the power rating of the resistor is not exceeded then, while the resistor will still get warm, it should not be dangerous.

If the resistor is getting too hot to hold, then as a seat-of-the-pants guess, the power rating is being exceeded.

You must realize, though, that a 12 watt dissipation (as with a 12 ohm resistor, i.e. 12 volts and a 12 ohm resistor) is still 12 watts, no matter what the rating of the resistor is. If you put in a 1 watt 12 ohm resistor into a 12 volt circuit, it will dissipate 12 watts and subsequently burn up shortly.
Pretty much so, but not as quick, if you place a 5 watt resistor in that same circuit, since it will still dissipate 12 watts.
And also, in due time, even if you used a 10 watt resistor. 12 watts will get dissipated.
And while a turn signal would not be on at all time, and a 10 watt resistor would probably work for quite a long period of time (due to the abbreviated duty cycle, on-off-on-off etc.) it is just poor design to use a 10 watt resistor in such a situation (what would happen if something weird made the turn signal "stick" in the always on condition?). It is much better to over-exceed the power rating to keep things cooler to the touch.

[ChuckE]

By the way, probably one of the best solutions is to do just as "Boar-Ral" did, and that was to hide the actual, existing bulb somewhere in the enclosure to be out of sight.

That way you can forget about trying to calculate how much resistance and wattage of a resistor is needed. The load of the LED assembly is much lower and should not affect the circuit otherwise, so additional fuse power concerns are not an issue.

Since the bulb is still in the circuit, it will still consume and dissipate the bulk of the power. It will still get hot, as any filament light bulb does. So be sure that wherever you place it, it can handle the build up of heat. So don't place it against a piece of plastic, unless you can cushion it with some heat resistant material (which would help in keeping the light from emanating out, also).