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2006 chevy trailblazer_ss_3ss
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On my GMT355 I needed load resistors on the brake light circuit and load resistors on the T/S circuit. Stock flasher and LEDs 100%. I needed the resistors on the brake circuit so my cruise control would work. Im confused what I need to do for the SS. :confused:

Do I just replaced the flasher module and everything still works?

or

Do I use load resistors, keeping the stock flasher, and everything works ok?

If I do use load resistors how should they be hooked up?

I'll be running LEDs 100% by next week. I dont mind using load resistors at all, but if I can just pop the flasher in and everything still works then awesome.
 

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2005 gmc envoy_sle_xl
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On my GMT355 I needed load resistors on the brake light circuit and load resistors on the T/S circuit. Stock flasher and LEDs 100%. I needed the resistors on the brake circuit so my cruise control would work. Im confused what I need to do for the SS. :confused:

Do I just replaced the flasher module and everything still works?

or

Do I use load resistors, keeping the stock flasher, and everything works ok?

If I do use load resistors how should they be hooked up?

I'll be running LEDs 100% by next week. I dont mind using load resistors at all, but if I can just pop the flasher in and everything still works then awesome.
If you are good with a solder iron, you can read my Post (Georgeplo) on Page 6. Or you can buy the LM487 (GM#10383322) and you have to read DOORMAN Post on Page 6 and have to use 1 small resistor instead of Load Resistor. So far my old module still working, and everything still works in my Envoy.

Hope this help.
 

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2006 chevy trailblazer_ss_3ss
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15 Posts
.15 Ohm 5 w resistor for running all LEDs? is that the same as 15 Ohm 5 w resistor? does the resistance matter to stop hyper flash when I hit the brakes? Thats my problem.
 

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2006 chevy trailblazer_ss_lt
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hope you're not dropping 14v across a .15ohm resistor, you'll need to upgrade your battery
 

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2006 chevy trailblazer_ss_3ss
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Long story, Re-wire to put in Quad REd LED Brake light and 2 LED Amber Turn Signal, Hyper flashing on Turn signal. Find and read this thread. Put in part# LM487 from NAPA, everything work fine except my remote car starter.

Take a while to figure out.

Thanks to doorman post on page 6 of this thread. Find out the LM487 have 4v on the brake line ( terminal B ) on the new Flasher relay. THat why my Remote start won't work, because it sense the Brake is on. (That will make the Cruise control not working as well ).

Take apart my old GM OEM Flasher, part# 12450284. Find out they use U643B Flasher IC. Download spec for the IC. Figure out how the chip works.

Do some math, here what I have to do, If you have a solder iron:
(Pictures of the module on Page 3 of this thread)

- If only replacing rear TURN SIGNAL to LED
Replace the Metal strip on the old Flasher module to .10 ohm 5W resistor.
Be careful make sure the legs from the Resistor not touching any other metal parts in the module.
DO NOT JUST CUT THE STRIP, have to remove it out the the board.

- If you are replacing ALL TURN SIGNAL to LED
Replace the Metal strip on the old Flasher Module to .15 ohm 5W resistor.
Be careful make sure the legs from the Resistor not touching any other metal parts in the module.
DO NOT JUST CUT THE STRIP, have to remove it out the the board.

Right now, I'm using the old module with the .10 ohm 5W resistor, everything works. Turn signal flash normal. Remote starter works, Cruise control works.

I will post again if there are any new problem show up.

:):):)

I was told I needed a .15 Ohm 5W resistor to stop my hyper flashing when I have my T/S on and brakes applied with 100% LEDs. I cannot find a .15 ohm 5W resistor just a 15 Ohm 5w
 

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2003 chevy trailblazer_ls
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2005 gmc envoy_sle_xl
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http://www.circuitspecialists.com/prod.itml/icOid/892

thats a .22ohm 5watt resistor i also found 1 at this cool site they also have cool infrared led's im not sure if its suppose to look like a little round resistor or a square one.

http://www.westfloridacomponents.com/WW544PD/5W+0.15+ohm+.15+ohm+Power+Wirewound+Resistor+Dale+LVR-5.html

not sure which to get??.. any ideas?

You can get the resistor from www.newark.com

http://www.newark.com/irc-tt-electronics/caw5r150jlf/resistor-wirewound-0-15ohm-5w-5/dp/40M8196?Ntt=40m8196

http://www.newark.com/ohmite/45fr15e/resistor-wirewound-0-15ohm-5w-1/dp/64K9065?Ntt=64k9065

Both will do the same. Hope this help.
 

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2006 chevy trailblazer_ss_3ss
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Bulk? I dont see where you have to order bulk amounts.....anyway I just ordered from newark. thanks for the site. I just dont understand why I have hyper flashing with regular bulbs in right now. Will this resistor install work for me?
 

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2005 gmc envoy_sle_xl
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Bulk? I dont see where you have to order bulk amounts.....anyway I just ordered from newark. thanks for the site. I just dont understand why I have hyper flashing with regular bulbs in right now. Will this resistor install work for me?
First, I own a Envoy XL, so it may or may not work with other GM or Chev. If your module Part# is the same as on Page 3, it is design to work the same.

Which Flasher unit do you have right now? If you have the orginal flasher and all regular bulb, you do not have to change. The flasher is design to hyper flash when 1 of the regular bulb is burnt out. So check all Turn signal bulb, and Stop light bulb, 1 of the bulb have to be out. The .15 ohm resistor is for changing all bulb to LED on the orginal Flasher Module.

I still using the orginal Module with the change to 0.15 Ohm resistor and All LED on all Turn and Stop light. Everything still works.
 

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2002 olds bravada
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RadioShack has .47-ohm 5w resistor

RadioShack has .47-ohm 5w resistor...
....will that work for the led-fix on this GM flasher...???

(i see .15 ohm and .22 ohm mentioned herein...)
 

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2005 gmc envoy_sle_xl
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RadioShack has .47-ohm 5w resistor...
....will that work for the led-fix on this GM flasher...???

(i see .15 ohm and .22 ohm mentioned herein...)

Which Flasher Module do you have? Read Page 7 on this Post. You can use 2 of them in Parallel that will give you .235-ohm. That close enough. Except it may not have enough room inside the casing for 2. Don't try to use one .47-ohm, it will get real hot.
 

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2003 chevy trailblazer_ltz
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Using the equations E=IR and P=EI, we find that 12 volts divided by .47 ohm is approximately 24 Amps. 24 amps multiplied by 12 volts is 288 watts of power. The typical bright filament uses 27W, so work backwards from there and be sure that the resistor is the correct power rating, otherwise, if it overheats, it could destroy itself. (of course, it is never actually 12V)
 

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2004 gmc envoy_slt
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538 Posts
So did we ever come to a final solution and the way to go...I'm going with quad brake lights and all LED (to include my mirrors).......i'm doing my retrofit with the tsx projectors in headlights and i already have all HIDs....LEDs last to do with that part
 

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2004 chevy trailblazer_ls_ext
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Using the equations E=IR and P=EI, we find that 12 volts divided by .47 ohm is approximately 24 Amps. 24 amps multiplied by 12 volts is 288 watts of power. The typical bright filament uses 27W, so work backwards from there and be sure that the resistor is the correct power rating, otherwise, if it overheats, it could destroy itself. (of course, it is never actually 12V)
Your calculations are correct, but only if you are adding a resistor in parallel with the LED bulb at you tail light. There are two ways to overcome the hyper flash condition when converting to LED bulbs.

The flasher module actually measures current draw on the Turn signal circuit. In case one of the bulbs burns out the current draw is reduced and hence the Flasher module starts to hyper flash. The same problem is seen with LED bulbs as they draw very little current. So most times people add a load resistor in parallel with the bulb to simulate the current draw of a bulb.

The other method is to actually modify the flasher itself to make it think that it has higher current draw. The 0.15 ohm 5W resistor is used to replace the existing shunt resistor inside the flasher module. The way this works is for example you have 2 amps flowing through the circuit, when you measure the voltage drop across the 0.15 ohms you will measure 2 X 0.15 = 0.3 volts. The Flasher IC is looking for a specific voltage drop across the shunt resistor to flash at certain intervals.

In either case you are actually tricking the flasher to think that it has the correct amount of current draw and so it flashes at a slower rate. However in either case if there is a blown LED bulb you would notice the typical hyper flash that is noticed when using a regular bulb.
 

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2002 chevy trailblazer_lt
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I have upgraded a majority of my rear lights to led's but i now keep blowing the stop fuse (#34 in the veh). I have rear turns and rear brake led's and license plate leds. Do i need the napa part to make this all work or is there something else like with the resistors?
 

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I have upgraded a majority of my rear lights to led's but i now keep blowing the stop fuse (#34 in the veh). I have rear turns and rear brake led's and license plate leds. Do i need the napa part to make this all work or is there something else like with the resistors?
Vleds sells 3ohm resistors that will work with up to 4 leds..either install in the front or back....gonna be going with led's once I get my ascender tails.....
 

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2005 chevy
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I just ordered a set of switchbacks from autolumination.com. I found the LED flasher relay on Rockauto.com for $32, so I figured I'd give that a shot. Guess we'll see if all these play well together
 
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