Turn Signal Flasher

[BlackDragon]

Looking for a part number so that I can swap out the flasher on my 2004 SE. I'm wanting to install an electronic flasher so that I can go to LED turn signals.

Thanks in advance.

[Tebore]

Starting in the 99+ Grand Ams the flasher is inside the multifunction stalk. So you won't be able to swap em. There's no point to LED signals either as LEDs aren't nearly as bright as stock bulbs.

[Wandering Mind]

Ok, first off. The turn signal flasher is located within the hazard switch unit in the center console, not in the multifunction stalk! You can't swap it out easily. I have schematics, I'll look into doing a write up on retrofitting a heavy duty adjustable style flasher for LED bulbs. This has been an idea in the back of my head for a while now, and it's nice to know someone else wants to do the same. I'll try to remember to get on that soon.

Second off, I have LEDs across my front end with the exception of my headlights and fog lights - who cares if LEDs are not as bright as halogen. They are bright enough. I don't think OP asked us if we thought they would be bright enough...

There's a trick you can do to "satisfy" your turn signal flasher. I use a 6 ohm, 50 watt power resistor (white ceramic block looking thing with a wire out each end) spliced between the flasher wire for the turn signal bulb, and the ground wire. This fools the flasher into thinking a halogen bulb is there, because halogens have a much higher resistance than LED bulbs have. With a power resistor installed for each turn 3157 bulb retrofitted with LED bulbs, the flasher works as expected with one drawback. If an LED bulb is not functioning for whatever reason, the flasher's rate of flash will indicate that it believes everything is working as expected. The resistor idea is not ideal, but it works.

Note. The front corner lamps under the orange reflex reflectors on the headlamp assemblies (194/168 size) reverse polarity depending on whether the headlights are on or off. With the headlights off, one wire is positive, but with the headlights on, the same wire is negative. It's screwy, but it's GM. Two things can be done about this. You can either look on ebay for 194/168 unpolarized LED bulbs (they have a tiny bridge rectifier built into the base of the bulb), or you can install a bridge rectifier into the wiring yourself and use any 194/168 in your corner lamps.

Further questions? Let me know. I've been there, and done that, with the exception of retrofitting a heavy duty adjustable flasher unit in place of the stupid hazard switch and flasher combo unit.

[Wandering Mind]

Update. I recently found my spare flasher unit and its associated wiring, along with the schematics I needed. I need a few 3157 halogen and LED bulbs for testing purposes. I might pick up some halogens tonight, and pull my LED bulbs from my car for testing later.

I'm working on a mod which will not involve cutting or splicing any wires in the harness. It'll be a modification to the electronics inside the hazard switch and turn signal flasher unit itself. It shouldn't be too difficult, honestly. I just don't have the time to sit down and work on it at the moment.

If what I'm thinking of actually works, we can keep the hazard switch / flasher combo unit and have our LEDs too.

[Wandering Mind]

The shunt GM is using in their flasher unit is making modification a little difficult...

[Wandering Mind]

Ok, so today I sat down and experimented a little bit with a spare flasher.

Here are my findings.

When you open the flasher unit up by sliding the green sleeve off, you'll be met with black, blue, and red plastic. Don't worry, it stays together, so no parts will go flying.

Looking at the bottom of the hazard switch/flasher unit, you'll see a little microchip. Around the microchip on the bottom there, you'll see three resistors. They'll either have color bands, or they'll be small black rectangles with these numbers on them:

152
511
393

If you place the flasher with the red plastic facing upwards, and with the pins to the car pointing to the right, the resistor you'll be looking to replace will be the resistor to the lower right of the microchip. It is currently a 39K ohm resistor.

I have found that without any bulbs attached to the flasher, and with that 39K ohm resistor in use, the flasher suffers from "hyper-flash" as expected.

I removed the 39K ohm resistor from the board, and soldered a 100K ohm resistor in its place. This has eliminated the hyper-flash from the flasher unit - with absolutely no bulbs connected to the flasher unit. After attaching one 3157 halogen bulb, it still worked perfectly. Next I tested it with one 3157 LED bulb, which also worked perfectly. I imagine this 100K ohm resistor value could be tweaked a bit for better performance (i.e. a more "normal" flash rate) but the flash rate with the 100K ohm resistor mod is easily street legal. On the test bench, it seems just a touch slower at flashing the bulbs than the factory rate of speed. Most importantly though, the Burned Out Bulb feature (hyper-flash) is all gone!

Bear in mind, DOING THIS MOD TO YOUR FLASHER/HAZARD SIGNAL UNIT WILL ELIMINATE THE BURNED OUT BULB FEATURE!!! Your turn signals will no longer do double duty when you have a burned out turn signal bulb.

Your next notification that you have a turn signal bulb issue may come from a police officer pulling you over for "not using your turn signals." Don't blame me if you get pulled over for your turn signals not working!

Even worse, if your turn signals are not functioning properly on the outside, but you think they're working based upon the dashboard lights and the clicking, you could end up in an accident resulting in severe injury and/or death to yourself or someone else.

By performing this modification to your hazard switch/turn signal flasher, you agree that only you can be held liable for any damages which may occur as a result, either direct or indirect.

So far, it's either this modification to the flasher unit itself, or adding load resistors to the appropriate flasher bulb wires. Those are the two solutions I have come up with. I'm currently using load resistors (5 ohm, 50 watt), and have been for at least 6 years without issue, however I never did like the idea of them. My goal was for adding LED bulbs to reduce lighting current draw and to enhance the coolness factor, not to add heavier than normal loads to compensate for the reduced resistance of an LED bulb.

I'll be removing the load resistors this weekend, and installing my modded flasher. An update will certainly follow.

Pics of the modification will come soon.

Next up on my list, to figure out how to keep the hazard switch part, and replace the rest of the flasher unit with a variable load LED capable flasher. This may take a bit, since I just figured out this resistor method and am going to use it for a bit.

[Wandering Mind]

http://www.gaownersclub.com/forum/sh...82#post1683782