I grabbed this from a post on ls1.com since we seem to get the question asked a lot... posted by Wayne (xbchbum)

Even better write-up that contains nice pics - http://www.blackcamaro.com/antenna.htm


Power Antenna Install Procedure

Thanks to RCowan99SSConv for this procedure! Also Thanks to RoadHazard, smiley, SShevy, and warpig!

Parts list:

GM Black Electric Antenna part number 10402860 (The chrome is available also, different part number)
18 gauge wire
Radio Shack Catalog # 276-1430. "25-position Female, D-Subminiature, Crimp-Type Connector kit"
Two Tap Splices (for power and ground from antenna)
One Butt Splice (for remote relay, green wire, on antenna)
A few zip ties to anchor wire routed from the dash to the trunk.
A length of surgical tubing to extend the drain tube.

Optional: Rocker or Toggle switch (if you want control over the antenna)
Two Quick Disconnects (for connecting the wire to the switch)

Before you start disconnect the negative battery cable!

For power and ground to the antenna I tapped into the factory amp which is near the antenna location. This connector has a load of wires, but you will notice 2 orange wires side by side and 2 black wires side by side on this connector. The orange wires are ignition switched power leads and the black wires are ground. I connected the orange from the antenna to the orange from the Amp. I connected the black on the antenna to the black on the Amp. Both of these wires were connected using Tap Splices from Radio Shack. They are like Vampire Taps in Network Cabling. This way you do not have to cut the factory amp wires.

For the signal wire (this causes the antenna to raise and lower), I used 18-gauge and ran it from pin #8 on the back of the radio allllll the way back to the green wire on the antenna. The connector needed for Radio pin#8 is Radio Shack Catalog # 276-1430. "25-position Female, D-Subminiature, Crimp-Type Connector."

That 25-pin connector kit will come with 25, imagine that 8-), tiny female connectors in it. All you want from the kit is one of those tiny female connectors. You break one off of the strip of metal (you'll understand this when you see it) and then crimp that little female connector onto the end of your wire. Then you just stick that connector into the back of your radio wiring harness where pin#8 is. It will slide right in that tiny hole and when you plug it in, you will find it fits snugly over the pin.

The trim piece around the radio has four spring like clips holding it on. The are positioned two on each side. I just got my fingertips under the top of the trim and slid them around to the passenger side and pulled that side free, then the other side. I disconnected the fog and ASR switches to get the trim piece out of the way. You will see the screws that hold the radio in. Remove them and slide the head unit out.

When you pull out the wiring harness from the back of your radio, there are two rows of pinholes. The top row is in a black plastic piece and the bottom row is in a white plastic piece. The pinholes on the black plastic piece are numbered 1-10 from RIGHT to LEFT. So... from the left side is pin #10..9..8 There will be a hole with no metal fitting in there at location #8. If you had a Pontiac there would be a wire here that goes back to the antenna.

Before you go to the trouble of running that wire back there, Go ahead and hook up the orange & black wires from the antenna to the amp. Then crimp that tiny female connector onto one end of the wire you plan to run back to the green antenna wire. Put it in the radio wiring harness and run the other end back to the antenna and connect it to the green wire.... Do this by just laying the wire over the seats & stuff, just as a test before you start removing trim panels.. and see if the antenna raises when you turn on the radio and lowers when you turn it off, etc. If you want incorporate a manual over-ride switch, simply splice the switch into the wire that runs from the radio to the antenna.

Then you can start taking out trim panels for your final installation.

Remember, remove the negative terminal from the battery before you begin installation!!

Some notes from the install:

The antenna mounting bracket needed to be bent somewhat to conform to the mounting surface behind the spare. I also had to drill a hole in the mounting surface. I used the mounting screw from the factory static antenna. The antenna drain tube was way too short. So I slipped a length of surgical tubing over the end to extend it. A hole must be drilled in the floor of the trunk for the drain tube. Be careful not to catch the bumper cover.

I installed a rocker switch so I could control the antenna since I listen to CDs more than the radio. When the switch is off and the radio is turned on, the antenna will not raise. While the radio is on, the antenna can be raised by turning the switch on. No matter which position the switch is in, the antenna will lower when the radio is turned off. (If the wire from the radio is run directly to the antenna, the antenna will raise when the radio is turned on and lower when the radio is turned off). My car is a convertible so I mounted my manual switch next to the power top switch. The convertible top switch was difficult to get out of the cover plate. It took awhile to cut and file the rectangular hole for the manual antenna switch. A Dremel tool would have been helpful.

Antenna Maintenance:

The mast should be cleaned from time to time. To clean the mast:

1. Turn on radio to raise antenna.
2. Dampen a clean cloth with mineral spirits or equivalent
3. Wipe the mast sections with the cloth removing any dirt.
4. Wipe dry with a clean cloth.
5. Cycle the antenna up/down
6. Repeat as needed.

Do NOT lubricate the antenna. Lubrication could damage it!
If the antenna does not go down when the radio is turned off, it may be damaged or need to be cleaned. In either case, lower it by hand by carefully pressing the antenna down.
If the mast portion of the antenna is damaged, you can easily replace it. See your dealer for a replacement kit.