94 GMC - tach and locks

hello there... im a long time reader and first time poster, here is what i have ...

1994 GMC extended cab 2wd 305 wA\T, and will be installing a Audiovox APS-786. I have a couple of questions,

1. Can i take my tach singnal from behind the dash where the TACH is , i mean the wire that leads to the littel motor that drive the tach , or do i have to run the wire throught the firewall and grab the WHITE wire at the ignition coil, or the ECM by chance?

2.I have positive door locks, do i use the 5 wire setup exactly as shown in the Door locks section of the forum? seems like i do, but i want to make sure before i start blowing motors

Thanks

i dont think you can grab the tach at the cluster.  i think on those trucks the cluster has a set of contacts that plug into the harness, and it unplugs when you pull the cluster out.  on the 2000+ GM trucks you can pull the cluster out and use the only white wire in that harness for the tach.  go to the ecm behind the glove box for your tach wire,  its pretty easy to go to.

for locks, 5 wire (type C) on the two door models, and its a positive trigger (type A) on the four door and keyless entry models.  lock is light blue, unlock is BLACK/ red

i just did one of these trucks last weekend and i reached up to the door boot from way down in the drivers kick panel and pulled a few harness down and out a little into the cab.  i found the 5wi lock/unlock in a harness and made my connections there.  it was easier than doing it between the body and the door in that rubber boot.

thanks for the help , i thought i didnt think i needed to reverse the polarity like mentioned above for these locks as the audiovox can go either way

so i will be doing it this way https://www.the12volt.com/doorlocks/page3.asp#5w

because i found this think https://www.the12volt.com/installbay/forum_posts.asp?tid=22554&KW=93+chev+lock

and was a little confused, thanks alot guys your great, some of the other automotive forums ive been to are a little bit on the wacky side, everything else seems straight forward

Thanks Again !

Just to piggy back on my original question, obviously the truck doesnt have a trunk.

So what do i do with the trunk wire from the module since i wont be using it , do i just ground that wire, or tape it off like the rest of them. Im just curious since i wont be using the trunk release button ?

Thanks