1997 Camry Tach Wire?

I'm installing a remote start on a 97 Camry 4cyl. The wiring info I've got lists the tach as blk/orange at the ECM behind the glove box.  There are three black and orange wires in this bundle, but none of them test corretly as the tach wire.  Anybody done one of these know exactly which wire it is, or perhaps another place I can grab the tach?  Have it running tachless off crank time right now, but I would much rather hook up the tach.Life moves pretty fast; if you don't stop and look around once in a while; you could miss it.