Alarm all haywire!

Hi everyone! I'll try to lay this out as easy as possible:

The situation: I'm setting up a 3 in 1 alarm (Prostart 3in1 by Autostart) alarm/keyless/rem.starter

The vehicle: '90 Ford Taurus GL  3.0L V6

The problem: After setting up all the wiring incl. siren, hood pin, shock, etc.. The moment I hook up the main harness to the 'brain' the alarm goes off for about a minute but is still armed when it stops. I've tried all the suggessted programming methods with the hood pin, program assistance button and valet, even dip switches. And I can't use the keychain cuz it needs to be programmed first. So in other words; power goes on, alarm goes on and stays on.

Could there be a mixup in the wiring- I went over it all at least 4 times, digitally probed everything but with no improvement. I even tried to hook up the main harness only but with the same results.

Could the problem be with not using the same gauge wire in the ignition wires? Should I just connect the main 12v wires straight to the battery? (There's was no noticible voltage drop in any of the wires)

Could I possibly have tapped into the wrong wire for the Tach? (Should I be testing it for 12v DC or AC?) where else can I find a tach wire equiv. in the engine- I've heard of getting one via spark plug, but how would I do that?)

Could an improperly grounded siren, or anything for that matter be cause for concern? Or is it car related? I know that the rear defroster and driver's controls for pass. windows don't work (yet all the fuses are fine). I've also heard of malfuntioning BCM's but I don't know if I even have one- and would it even affect the alarm install?

Well, I know those are a lot of questions, but to me it's still one big problem so to anyone reading this, please try and answer as much as possible.

Thank you all SO much!

Hi, I've tried all I can with the valet and even the hood pin but it still will not disarm or respond to any programming attempts.

As for the Tach, right now I have it tapped into the (-) TACH wire at the ignition coil (which I found in my repair manual). I don't know if it works cuz of problem #1. But would this work as well? Is it AC? Cuz I tested it with the engine running and in ignition run position and it tested about +12vDC. Should I try testing for AC?

Thanks!

Yeah, I've read the manual quite carefully- and it's exactly as you outlined it with no results. I've tried it while the alarm initially goes off when the main harness is plugged in and also after the alarm goes off (but is still armed).

I did find a smaller gauge wire in a separate harness in the steering column that has the same colors as the larger gauge ignition wire. Could this be anything I might need to tap into with like a 2nd ignition or something?

Anyway, here's another question; I set up the 5wire alternating relays for the locks and when I press either lock/unlock from the driver's door it sounds like it isn't getting enough power and doesn't move anything. But, the locks work fine on the passenger's door. Could I have tapped into the wrong motor wires or placed them on the wrong relay? Also, the +12v supply to the relays is linked (fused) to the battery terminal.

Thanks for your ongoing support! 

One more thing, might I be able to utilize the arm and disarm wires from the alarm? I don't have factory items like RKE. But I just thought they might still be used somehow?

And another, do I need to connect the Ground Out While Running wire from the alarm? What's a good place to put it? Should I just ground it to the body?

thanks