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Changing flasher relay FOR LED TAIL LIGHT BULBS

2002AVA

2002AVA

Full Member
Joined
Jan 14, 2005
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3,152
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Coarsegold, ca
I am currently running LED bulbs as rear tail light and blinkers. The LED use far less power than factory so my blinkers are blinking extremely fast. Like they do when you have a bulb out. They make a flasher relay to fix this issue. Problem is I do not know how to get my current flasher relay out. Any help would be grand.
On a side note did you know your hazards and blinkers are 2 separate bulbs? The top bulb in the tail light is your hazards and the second is your blinker. Just food for thought.
 
Not sure how those work with our trucks
I had LED tail lights before they came out with these flashers. At the time the fix was to add a load resistor.
I've been running one for probably 10 years with my Spyder LEDs and it never give out so I haven't had the need to try the flasher yet.
 
Ok I am running 2 30 LED light bulbs for the tail, brake and blink. I plan on adding more bulbs but they are $40.00 a piece because I went with the top of the line. That is why I am thinking flasher. Super righted make a zero to 12 VDC FLASHER for the 02 Avalanche. 
 
Our trucks have an integrated flasher module. There is no separate flasher relay as some other vehicles have... Last time I looked the factory module was like $150 to replace so you don't want to mess with it.

The only option is a load resistor for each turn signal. You also need a load resistor for the passenger side brake light as well to maintain your Cruise control.

As to your lights... The dim portion is your parking lights...

As talked about elsewhere the top bulbs bright portion is the Brake Light and the bottom bulb bright portion is the turn signal/hazard.

There is a mod to combine the brake and turn signal functions in both bulbs if only one function is required.. (Ie brakes will light BOTH lights if no turn signal... BOTH lights will light if no brakes while turn signal is on.. If turn signal while brakes are on then will work as normal..)

 
As Rodney said the passenger rear tail light brake LED also needs the load resistor or your cruise control won't work. If you have a remote start, that won't work either without the load resistor. Even if you could change the flasher, you'll still need to add the load resistor to maintain the two features I just listed. In my opinion, there's no point going through the hassle to replace the flasher if you're still going to need a load resistor for the cruise control. Unless you have no plans to use your cruise control ever again, you might as well nix the idea of a LED flasher.
 
May want to check into the flasher module further. The 2002 has some really weird setups that aren't the same in 2003 and newer.

I checked into this a few months back and it appeared the avalanche had an all inclusive module that controlled the flashers. Atleast on the 2003-2006. A replacement module was $150 and had no user serviceable parts such as removable relays. I just looked on Rock Auto and they show replacement relays now so I am confused.

I have exams in the morning but I can look in my shop manual later in the week. I would look in the underhood fuse panel and in the left hand side of the dash fuse panel. There MAY be a fuse panel on the 2002 on the right side of the dash as well.

Again I will double check when I get a chance
 
I have an early 02 and the flasher is a relay-looking item that lives in front of your left knee when driving.  You need to remove the knee-panel to get to it.  I just replaced the stock one with:

1999-2002 Chevrolet Silverado LED Turn Signal Flasher, EP29

http://www.amazon.com/gp/product/B00KQUXR9K/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

And it works with the front turn signals converted to LED.  I haven't converted the back yet, but I'll let you know how I get on regarding cruise control.  Why does the light affect the cruise?!
 
The brake lights affect the cruise control.

Let's talks some Physics real quick.

Matter is made up of molecules and all molecules are made up of atoms. Atoms consist of protons, electrons and neutrons.Electrons have negative charge, and protons positive and neutrons are naturally neutral. Therefore the electric charge depends on how much electrons and protons it contains.

Basic electrical theory dictates that matter is positively charged if an atom in the matter contains more protons than electrons, and negatively charged if more electrons than protons are present. Therefore, when considering polarity, how much charge an object has is equal to the total amount of charges of all the atoms.

In order for current to flow there must be a continuous path from the negatively charged source to the positive. The electric charge moves to create current. How quickly the charge changes in a set amount of time determines the electric current. This current flows in the opposite direction of the way the electrons flow in the circuit. Because the electrons always flow from low potential to high potential (negative to positive), the electric current flows from positive to negative. The current will always take the path with the lowest resistance.

How much opposition the conductor or metal wire presents to the electric current flow is the electrical resistance. The lower the resistance, the easier current will flow. Think of current like water flowing through a pipe, if the pipe is small there is more resistance to water flow, if the pipe is large the water will flow much easier. A larger wire size will allow more current to flow.

Same can be said for LED versus the stock incandescent bulbs in our vehicles.

When you put LEDs in place of the normal bulbs you have issues as the resistance of the LED is less than the stock bulbs. Two things happen as the lower resistance allows the current to flow easier and the truck thinks the bulb is blown hence the flashers blink faster and in the case of the brake light,  the truck thinks you're constantly applying your brakes because of the lower resistance of the LEDS. As you know, when you apply the brakes the cruise control shuts off so if the truck thinks you're constantly applying the brakes because it is not getting the correct resistance from the bulb, the cruise control will never come on.


LOL. Pardon the long and winded explanation. I couldn't help myself.

 
Never mind the long-windedness - that is an awesome explanation from first principles!

I've just put LED rear flashers in (amber in the backup lamps, as part of my Euro light conversion) and the relay I listed above maintains the correct flash rate with all four LED bulbs.
 
I purchased a set of LED tail lights with the resistors built in. They work perfect as does my cruise and everything else.
 
As to lights...

For the 2003-2006 minimum (And likely 2002) I have video'ed the rear of my truck and Brake lights are definitely the top bulbs and turn signals AND flashers are definitely the bottom bulbs. The only difference between flashers/hazards and turn signals is one does only one side and the other does both sides.

I have since done the 4 light brake/turn signal stuff and you can certainly tell the difference. With my LED tail lights however it is harder to tell the difference with the lights on than it is with them off. They could have made the difference more pronounced...

Rodney
 
So replaced all lights with led. I've put in resistors for front turn signals and two for back. However there is four light plugs in the rear so I installed the resistors on lower light plugs. Turn signals work fine until I applied the brakes then turn signal stops blinking in the rear. The top plugs I'm guessing need resistors as well. What wires should be connected to resistors? Any help would be appreciated. Thanks
 
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