2000 silverado and ultrastart 1272

I think I confused the tach learning procedure and believe you did it correctly. I'm out of ideas for the moment. I don't install with Ultra Start and was thinking of a customer owned unit I was installing recently that never learned tach and your procedure for tach learn sounded similar to the system reset procedure but I just checked the install guide and realized it's different. It just sounds like something with the starter/wiring if it won't takeover after it's running with the key. Generally after about 1-2 minutes of running with the key, the immobilizer is no longer checking and the remote starter should be able to take over at that point. If it doesn't, either the ignition wiring is not correct or the tach signal wasn't learned or is failing.

Thanks. I will check the Tach signal again, I went to a wire behind the gauge cluster. Maybe it's wrong. I'm just so frustrated. However, it dose make sense that if the truck is not getting the tach signal, the Fortin won't program

Just want to clarify, the Fortin should program regardless of tach being correct or not. I'm just remembering now though that when I had the issue with the Ultra Start not learning tach, it wouldn't even try to start the car I was working on. It would just flash the lights 7 times. So again, your tach signal may be correct after all. On the truck, it's usually a white wire coming from the harness behind the cluster. Test it (if you haven't already) with your meter on AC volts, black to ground and red lead to that white wire and start the truck. You should get somewhere from 1-6 volts that increases when you hit the accelerator pedal.

Try to replace the Fortin and see what happens. Just for giggles.