prostart 3371, 1994 gmc sierra

Alright guys, i desperately need your help! I know that the remote start module is far from the best on the market but my father didn't want anything fancy and just wanted it to start his truck after work. I have installed 1 remote start previously on my 97 ranger with minor issues. I have basic electric knowledge as i am a 3rd year mechanic. Anyways heres the info... The truck is a 1994 GMC Sierra. It had an old "Command Start" system in it previously (1500/1600/1700/1800 model) so i figured it would be easy, boy was i wrong. I found all the wires easily. Hooked up both Red constant 12v's, Yellow ignition, orange accesories, purple for the starter, brake switch, ground, tach, the only thing i didn't hook up yet was the door locks as i wasn't 100% sure about it. I plugged in the 2 harnesses and the reciever. It gave 4 flashes of the park lights which the manual says is normal. After this i can't get it to start, no cranking, no lights, no sound, no nothing. I tried learning the tach but doesn't recognize the procedure for it. I got it into programming mode using the antena but nothing i did helped. I know sometimes it can be something simple so i just need some ideas! Thanks!

Anybody have any ideas at all cause i'm stumped!

Unplug the remote starter and verify each wire with a digital volt meter. Make sure that all the old remote starter wiring is removed and all connections are good and new. Make sure that the ground for the new unit is into a clean, paint free spot on the chassis inside the truck. Plug the antenna in first followed by the 5 pin harness with the ground in it and then the 6 pin main power harness. Leave the 12 pin plug out till the unit is programmed. If the 3371 model has a small yellow loop of wire coming out of it, it needs to be cut for use on an automatic transmission. If you didn't cut it before you programmed it, you must do a complete reset on the module. The manual tells you how. Then cut the yellow loop and try programming the unit.sparky