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2003 gmc envoy_slt
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280 Posts
Envoy- Same? Different?

Are there any differences for the circuit board mod and the relay mod for an Envoy?
 

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2005 chevy trailblazer_ls
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916 Posts
So I got these relays wired up for quad brakes and turns......I got hyper flashing while using my T/S and applying the brakes, how do you correct this??
When you apply the brakes with the turn signals on, the relays alternate the power supplied from the brakes and turn signal. I experienced this with my setup as well. I removed the relays from the system because I shipped the TB back to the US. It has to go through Customs & DMV inspections, so I went back to stock. When I get the TB back, I'm going to reinstall the relays, but I'm going to draw the power for the turn signals upstream from the flasher module under the dash. Once it's finished and working correctly, I'll draw up a diagram and post it.
 

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2006 chevy trailblazer_ss_3ss
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15 Posts
all of my problems were solved by installing to .15 Ohm resistor in my flasher relay. Thanks again for all the info guys!
 

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2006 chevy trailblazer_ls
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198 Posts
so if i understand this correctly the middle/signal light will also be a running light when you are driving so all 4 light would be on when you are just driving and it would still function as a blinker too? and the top lights would still be running/brake lights?
 

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2003 chevy trailblazer_ls
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525 Posts
so if i understand this correctly the middle/signal light will also be a running light when you are driving so all 4 light would be on when you are just driving and it would still function as a blinker too? and the top lights would still be running/brake lights?
:yes: That is correct.
 

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2005 chevy trailblazer_ls
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916 Posts
Well, since I returned from my job in Madagascar (laid off again), I finally had some time to work on the Quad Brake & Turn Lights. I connected the brake & turn signal bulbs together. Then I tapped into the turn signal switch upstream of the Flasher Module. I ran the wires through a soft plug in the floor board near the driver's seat, then inside the frame to the rear of the TB. When the turn signal is activated, power is supplied to a Bosch relay for each side as appropriate (left or right). The relay opens the circuit to the brake light. The turn signal downstream of the flasher connects directly to the bulbs, as does the brake circuit. I put a diode on the turn signal circuit to prevent reverse flow to the flasher. Refer to the attached schematic.
 

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2003 chevy trailblazer_ltz
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94 Posts
I completed this curcuit board mod and it worked fine until I installed my new LED Brake lights. Now the lights are back to stock. Is there something I can do to get the quad mod to work again?
 

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2008 chevy
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68 Posts
not quite sure what you have now.....

what does the taillight do now?

LED Bulbs or complete unit (make model of taillight)

did you do the harness and relays change with or without resistors?



 

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2003 chevy trailblazer_ltz
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94 Posts
I replaced the entire unit with the standard ebay LED tail lights. I'm not sure of the make or model number. I also added 6ohm load resistors to slow the sgnal down. The curcuit boad is still modified but the lights are not quad anymore. I did not modify the harness other than splicing the load resitor in, but the quad wasn't working before I did that.
 

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2008 chevy
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68 Posts
it uses the circuit board?? would you be able to post a pic or describe the connection....

if it uses the CB then it must plug in like a bulb - if thats the case you might want to try and turn the connectors around 180 in socket- sorry i really have no idea how these units hookup - i would have thought since its a complete unit it would not use the CB and just plug into the harness connector
 

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2003 chevy trailblazer_ltz
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94 Posts
You are correct about the way the lights hook-up. They have connectors that look like the bottom end of a standard 3157 bulb with wires leading into the housing. I have tried flipping the connectors around but the light doesn't work at all when I do that. These lights were less expensive than the others listed on ebay so I guess I got what I paid for. I was really wanting to have Quad LED's.
 

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2005 chevy trailblazer_ls
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916 Posts
One quick question do I only need 2 relays and 2 diodes? Or is that all I need for only one side to be like this?
Quad tail lights don't require any relays or diodes. Those are used for quad brake & turn signals. Which is another thread. There are numerous posts regarding the mod.
 

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2006 chevy trailblazer_lt
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137 Posts
Quad tail lights don't require any relays or diodes. Those are used for quad brake & turn signals. Which is another thread. There are numerous posts regarding the mod.
Yeah I understand that they are separate mods, but I plan on doing both of them. I'm just not exactly sure if doing the relay mod in one tail light would also affect the other?
I have yet to see any other threads on this subject.
 

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South Chapter
2008
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4,487 Posts
The easiest way to do this mod is to buy a donor pair of boards and add the socket connectors to the turn signal socket (center) for the parking/running lights....this will give you quad parking/running lights......for the brake/turn signal lights.....you will have to get a set of Jettstreams Quad light boxes......please note that Jettstreams Quad light boxes will not give your ride the quad parking/running lights, you have no choice but to add the connectors into the sockets....PERIOD! Trust me, I had the first set of Jettstreams quad boxes and they only will work on the signal portion of the light.....I had to take the boards apart and add the second set of contacts for the parking/running lights.....the contacts are not on any of the circuit boards that are available from anyone.......at least not yet!
 

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2006 chevy trailblazer_lt
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137 Posts
My local Radioshack only had 4 pin relays and I am wondering does it matter if the relay in 4 or 5 since we are only using 4 pins?
87 and 87a look basically the same so on a 5 pin relay where it connects to 87a couldn't I just connect it to 87 on the 4 pin relay?
Thanks to who ever can answer this question!
 

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2005 chevy trailblazer_ls
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916 Posts
My local Radioshack only had 4 pin relays and I am wondering does it matter if the relay in 4 or 5 since we are only using 4 pins?
87 and 87a look basically the same so on a 5 pin relay where it connects to 87a couldn't I just connect it to 87 on the 4 pin relay?
Thanks to who ever can answer this question!
You must use the 5-pin relay. Even though they may look the same, they have opposite functions. Pin 87a is normally closed, while pin 87 is normally open. When the solenoid is activated, then 87a opens and 87 closes. You want to open the circuit to the brake light while the turn signal circuit is closed.

Try the aoutmotive parts stores or online to find the relays.

Post #106 has a pdf of the diagram for tapping into the turn signals pre-flasher to control the brake lights. I have this on my TB and it works great.
 

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2007 chevy trailblazer_ls
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9 Posts
I'm in the process of doing the quad light mod and thought about using the extra contacts from the spare board on the reverse lights. I would solder a jumper wire between the 2 positive contacts and another between the 2 negative contacts. This way, both filaments of the bulb would come on when going in reverse. That would really light up the way while backing up on those dark country driveways.

May question here is: is this a good idea? or will it draw too much power, or will the smaller filament burn out quicker, or is there something else that I am missing here and that is why I haven't seen anybody do this yet. :thx
 

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2007 chevy trailblazer_ls
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9 Posts
I'm in the process of doing the quad light mod and thought about using the extra contacts from the spare board on the reverse lights. I would solder a jumper wire between the 2 positive contacts and another between the 2 negative contacts. This way, both filaments of the bulb would come on when going in reverse. That would really light up the way while backing up on those dark country driveways.

May question here is: is this a good idea? or will it draw too much power, or will the smaller filament burn out quicker, or is there something else that I am missing here and that is why I haven't seen anybody do this yet. :thx
Feedback...anybody... :worried:
 
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