Avalanche2003SS said:
So there really isn't a way to have have all 4 lights used for brakes and turns and have the turns override the brakes like the 07+?
Not without using the trailer lights...
I have the verticle LED lights in my truck and did this mod the way I suggest...
I used 4 diodes and a fuse on each side of my install... Original posting calls for 3..
You COULD do this mod with just 2 Diodes... But I STRONGLY suggest not.. I used 3 amp Diodes in my install. I would not go lower. Since I am using LED's the 3amp diodes are over kill. (I put my Load resistor for the brake lights upstream from the diode so the diode would not have to carry the current. Without the load resistor on the passenger side brake light the cruise control won't work.)
3amp x 12 volts = good for 36 watts...
The Mandatory Diode would be placed between the normal Brake light feed and the top (Brake) light high filiment. This prevents the turn signals from backfeeding through the brake system and flashing both lights. You attach the line from your turn signals at the outlet of the diode to the top light. (Line on diode pointed towards light)
The first optional Diode would be on the output of the normal turn signal lines. Since you cut the line for the normal turn signals to the bottom (turn signal) light you still should use the diode between the turn signal supply feed and the top (brake) light. This will prevent the brake lights from back feeding into the turn signal system. I call this optional because the system may already be protected against backfeeding but it still is a good idea to use it and the original instructions call for it and don't call it optional.
The second optional diode is the one from the turn signal feed to the bottom (turn signal) light. Since you will be feeding this from your trailer light system you don't need to feed from the normal feed line. HOWEVER, if you ever have an issue with the trailer lighting you will lose your bottom lights... I STRONGLY suggest installing this diode so if you DO lose the trailer lighting you still have your OEM turn signals... The previously mentioned optional diode then becomes mandatory from the turn signal feed to the top (brake) lights.
The 3rd optional diode and the optional fuse I used from the trailer lights to the bottom light. The fuse will blow if there is an issue and is a good idea regardless since you are tying two systems together. You can also then pull the fuse if you decide not to attach the trailer light to your bottom light. (Because an issue with trailer or something.) The diode is placed to prevent any sort of back feed from the OEM lighting to the trailer lights. This is in case you are pulling a trailer and you have an issue with the trailer lighting that blows a fuse on the trailer. You won't feed from the tail light system to the trailer system which will protect the tail light system. (Of course if you don't use the second optional diode then this diode is not going to do anything.)
On my system I have LED tail lights... I feel confident this system will be durable and will work. If I ever have an issue with trailer lighting the failsafe is for my turn signals to work as they always did and the brakes will as well. I just have the added turn signals when the brakes are not applied... I would not want to do this on an OEM system with standard bulbs. The power requirement of pulling twice the power through the same harness may eventually cause harness failure that will be hard to diagnose.
As it is the LED's are MUCH less power hungry than standard bulbs and should not see any issues...