LED Brake and Backup Lights
JK Jedi
Joined: Feb 2008
Posts: 7,215
Likes: 10
From: Georgia
Nah, as long as the resistors are close to the same resistance as the original light bulb, the ECU can't tell the difference.
Too bad the ECU causes the fast-flash. I guess there's a law that states that flashers need to indicate a bulb failure (hence the fast-flash), but with LEDs there is SOME current flow, not NONE (none indicates a failure). The ECU must use a current threshold rather than a "yes/no" current check, which is really too bad.
Too bad the ECU causes the fast-flash. I guess there's a law that states that flashers need to indicate a bulb failure (hence the fast-flash), but with LEDs there is SOME current flow, not NONE (none indicates a failure). The ECU must use a current threshold rather than a "yes/no" current check, which is really too bad.
JK Enthusiast
Joined: Mar 2008
Posts: 475
Likes: 0
From: Suffolk,VA
. The issue here is that the JK doesn' have a dedicated flasher unit, it's built into the ECU, thus it's not as simple as replacing the flasher.
JK Newbie
Joined: Dec 2007
Posts: 80
Likes: 0
From: Gretna, VA
select normal or fast
Some engineer went to great lengths to implement hardware and software to monitor the current draw of the turn signal circuit and change the flash rate (software) to FAST when a bulb fails. This enables the TIPM to behave just like the old electro-mechanical flasher unit and notify the driver of a fault! Adding the resistor increases the current and convinces the TIPM that all is well. The input circuit will not be damaged unless you reduce the resistance to the point that it looks like a short. I bet the output has overcurrent protection to protect itself in this case (ie a fuse). An interesting experiment would be to substitue values for the added resistor to determine at what point the TIPM starts the fast flash. This would allow one to use the highest resistance value(lowest current draw) to maintain normal flash rate and minimize the load. Or install a switch to allow the driver to remove the resistor and select normal or fast flash!
JK Super Freak
Joined: Nov 2006
Posts: 1,687
Likes: 1
From: trenton ontario canada
I would be happy with the fast flash something different and out of the norm so it may even work better
my question is cause led's are directional lighting.
can you see your rear side marker at night time?
please post a picture of the led bulbs you used. please js
my question is cause led's are directional lighting.
can you see your rear side marker at night time?
please post a picture of the led bulbs you used. please js
Last edited by WRAITHYJEEP; Nov 8, 2008 at 09:44 AM.
JK Freak
Joined: Mar 2008
Posts: 871
Likes: 0
From: Tucson, AZ
Going to look into the resistor fix some more. Sure wish there wasn't so much electrical technology in the JK (ie: tire inflation monitoring, power windows and locks, stability control)...
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JK Freak
Joined: Mar 2008
Posts: 871
Likes: 0
From: Tucson, AZ
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Did a search, and found this info for ordering the resistor kit:
eautoworks.com/product-Led-33226.htm
Not sure if I can find the same thing locally, like at Radio Shack...
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Did a search, and found this info for ordering the resistor kit:
eautoworks.com/product-Led-33226.htm
Not sure if I can find the same thing locally, like at Radio Shack...
.
Last edited by HappyCurmudgeon; May 4, 2009 at 05:16 AM. Reason: removed non sponsor link
JK Newbie
Joined: May 2008
Posts: 21
Likes: 0
From: London, ON
Current savings vs fast activation
Am I missing the point? I thought the reason for switching to LED's was to take advantage of the fact that they illuminate more quickly (and more abruptly), giving the other driver more time to hit the brakes.
Is an extra 2 amp draw, during the (relatively infrequent) turn signal use, that much of a big deal?
Is an extra 2 amp draw, during the (relatively infrequent) turn signal use, that much of a big deal?
JK Newbie
Joined: Aug 2007
Posts: 31
Likes: 0
From: RiderVille
There is no extra 2 amp draw. The led's and the resistor draw the same amount of current combined as an incandescent bulb. The taillights are then still pulling the stock current keeping everything happy. RedneckJeep does not know what he is talking about here with computers not liking resistance. The circuit is designed to draw a certain amount of current(determined by the voltage and resistance), and adding the resistors in parallel with the leds lights increases the current to this level. The computer is unhappy if it does not see this resistance, and does the fast blink.