I am going to install an alarm, starter on my 2002 Chevy Silverado. I says on installation instructions that some of the wires are located in the BCM. What does the BCM look like, Where is it located, and What will I have to do to get to it? Also, Where will be the best place to hook my tach wire to get a tach reading for the starter? Thanks for any help, mrsparky 637
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mrsparky637
The BCM is basically a computer with a a couple of plugs going into it. When you drop the underdash panel, you'll see the BCM you need dead center at the steering column with a bunch of plugs going into it. Can't miss it. Also drop the metal piece revealed once you remove the underdash panel. (4 10mm bolts) This will give you access to all your ignition wires as well..As for tach here it is:
TACHOMETER|NOT pnk, blk, or brn| |any ignition coil
Good luck,
Mike
If you remove the lower dash panel you can't miss it. Thats the panel in front of your knees when sitting in the drivers seat. You have an easy truck to work on. I've probably done 75+ of them in the last 5 years (from 99 to 2002 the trucks wiring is exactly the same).
For tach I usually use a wire at the PCM below the battery. There are about white 3 wires in there. One of them reads about 6.7 volts AC when the truck is running. The wires are a little difficult to get at, and the white wire you need is the most difficult white wire to get at. If you don't want to go there, you can also use one of the coil wires. On the top of the drivers side of the engine, you see a plug with about 8 wires in it. The light blue wire can be used as a tach source. Much easier to get at.