auto start problems

[toohott7718]

I just installed an alarm on my 2004 silverado base model, no power windows or locks, 2500 series if that matters. I was told I can hook this up without hooking up the tach wire, when I try to start it it runs for a few seconds then shuts off. let me know what I can do. at frst I tried to hook up the tach wire but where I was told to hook the tach wire (at pcm in a green plug) I never have found it. please let me know the easiest way I can fix my problem. thank you very much. customer id 41247