I have seen alot of shift light install questions as of late, so I figured I would post up a quick howto. I will add pics tonight and that should help make everything easier to understand.

First off, the way you should hook up your shift light is through the pcm, so DISCONNECT THE BATTERY!. The pcm is located on the passenger side of your car, under the hood. Once you pop the hood you should be able to see it all the way against the firewall. The PCM is divided into two portions. One of these will be blue, the other will be red. In order to see which connector is where, you need to remove the bolt on top of each pcm connector. Before you get too far into the pcm connectors, route your shift light wires through the firewall opening below the pcm. You should be able to route these wires through the hole without removing the pcm, but if you need to remove the pcm to do that then that is fine. Once your wires are routed through, open each of the connectors, you should be able to see pin assignment numbers. These numbers correspond to the wires you want to tap into in order to hook up your shift light. Tapping into a wire basically means that you are going to cut the wire going into the position you want, and you will then reconnect these wires along with another wire (one from your shift light). This will allow your shift light wire to receive the signal that was being transmitted from the pcm. On to pin assignments...

98 RPM Pin Asg: Blue #35 white wire
99 RPM Pin Asg: Red #10 white wire
00 RPM Pin Asg: Red #10 white wire
01 RPM Pin Asg: Red #10 white wire
02 RPM Pin Asg: Red #10 white wire

Red or Blue indicates which pcm connector the wire is on. The # represents the pin assignment for the wire. If you open up the correct connector and then locate the correct number, you should see a wire going into this position, and it will be white. This is the wire you want to tap into for your rpm signal. Cut the white wire about an inch away from the pcm or more (remember you are going to strip some of the wire off so you can connect this wire back, so make sure you leave plenty of wire to work with. In order to make my install easier I extended this wire so that I wouldnt have to stretch any of the wires and have to worry about them being pulled out) Once you have this wire connected you should be ready for the power wire.

For your power wire, you want to tap into a wire that is an accessory; you dont want your shift light to have power 24/7. A good way to hook up this wire is through the PCM ignition wire. This will turn your shift light on whenever you put your key into the ignition and turn it. The Pin assigment for this wire is the same on any LS1: Blue #19 pink wire.

Now you can connect your ground to any good ground. The pcm has bolts that hold it down, and any one of these will suffice. Now test out your shift light!

 

Good info. I'm installing an Autometer Cobalt Tach and it has an extra wire (white) labeled to go to "12V in dash lighting". Where does that one go?

Thanks

 

Oh oh oh, I know this one. That one will go to any Switched lighting, depending on when you want the "backlight" of the tach on. Many do this on the Fog Light switch or the "Straight Up" position of your head light switch.

Should be easy to find a wire, especially with the tach being mounted right above the fuse box inside the door!

Hope that helps!

Taco

 

i actually used the "add a circuits" for the white, and the red wires of the tach, this is so you dont have to tap any wires, but rather at a fuse and plug into the fuse box, cant even tell they are there because the fuse box cover goes right over it

jimmy

btw, add a circuits are like 5 bux a piece