Electrical Tail Light Indicator Stays On After Installing Led Tail Lights?

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Pate

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Oct 23, 2017

#1

• Oct 23, 2017

• #1

86 mustang gt and I just installed LED tail lights and now my tail light indicator on the graphic display warning system stays on? I put the original 1157 halogen bulbs in and it goes away? The LED work like they should which confuses me? Anyone else have this problem or find a fix?

 

Mustang5L5

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Oct 24, 2017

#2

• Oct 24, 2017

• #2

The display works off resistance in the bulbs. When a bulb blows, resistance drops, and the car displays the lamp.

Leds have very little resistance, so oem bulb out indicators usually have issues when using them

 

jrichker

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Oct 24, 2017

#3

• Oct 24, 2017

• #3

Mustang5L5 said:

The display works off resistance in the bulbs. When a bulb blows, resistance drops, and the car displays the lamp.

Leds have very little resistance, so oem bulb out indicators usually have issues when using them

Click to expand...

You have it backwards... Think about incandescent bulbs - they have low resistance in ohms and draw about .5 amps current per bulb. A LED is high resistance and draws .04 amps .

Current data is from: https://mattgadient.com/2006/10/12/...s-how-much-of-a-power-savings-can-you-expect/

 

Last edited: Oct 24, 2017

Mustang5L5

That is…until I whipped out my Bissell

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Oct 24, 2017

#4

• Oct 24, 2017

• #4

Don't post at 1am is all I'll say

 

P

Pate

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Oct 24, 2017

#5

• Oct 24, 2017

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So I need to add resistors or go back to original.

 

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FoxChasis

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Oct 24, 2017

#6

• Oct 24, 2017

• #6

The warning display circuit already has resistance wire in it. With LED bulbs in place the resistance wire value is not correct.

 

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Pate

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Oct 24, 2017

#7

• Oct 24, 2017

• #7

Sorry did not mean for that to double post

 

1hot87gt

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Oct 25, 2017

#8

• Oct 25, 2017

• #8

And be careful with the resistors. I tried to do the same thing on my ‘13 Ram and apparently those resistors can get so hot they can start a fire. Put your stock bulbs back in and call it a day. Just my opinion.

 

General karthief

wonder how much it would cost to ship you a pair

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Oct 25, 2017

#9

• Oct 25, 2017

• #9

Lets see if @Diode Dynamics can shed some light on this problem
See what I did there?

 

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Mustang5L5

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Oct 26, 2017

#10

• Oct 26, 2017

• #10

It's just the red tail light warning in the info cluster I assume?