Keyless Entry Killing Me, Need help with door locks

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Danspeed1

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Hello everyone,

This is my first post and I sure hope someone can help. I am having a heck of a time wiring in a compustar remote start keyless entry system in my 1994 K1500 2 door extended Cab 4x4. The remote start went in without a hitch however I have spent THREE days trying to wire in my lock and unlock functions without any success. I have seen other posts on her and a few other places and was able to locate the light blue wire at the kick panel as well as the black/white wire. (In other year trucks its a black/red) No matter what I do I can't get it to function correctly. I have used the Type C/5 wire reverse polarity configuration and unfortunately all I get is smoldering wires. When you give the black/white wire +12 volts the doors do open without an issue. However try that on the side with the light blue wire and all you get is sparks and smoldering wire. It doesn't make any sense to me. I went as far as to purchase a Directed Electronics 451m door lock relay hoping it would solve my issue. But its nothing more than a fancy relay. I reviewed a wiring diagram for the truck 1988-1994.... It appears as though the light blue wire is always grounded, unless the door lock button is pressed in which case the switch allows it to move a connection inside and the circuit becomes energized. Much like moving the switch from 87a (if it could be grounded) to 87 and having 87 at 12volts. The issue becomes when you energize the relay; the wire back feeds through the passenger door and grounds.

Dan
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Chris Rogers

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These are 5 wire locks. Google should be able to help with it.
However:
Find the lock wire off the left door, cut it in half. Using the relays you bought do this:
85 - alarm
86/87 +12v use heavy cable for this
87a switch side of cut. ( use a meter to determine this)
30 lock motor side of cut.

Do the same for unlock and stick a 20a fuse on the 12v supply. Saves a smoke show from happening.

The net result will be that the switch still works and when you pulse the alarm wire to ground the doors will lock/unlock as you are essentially mimicking the OE switch with relays.

The system rests at ground.

Give that a shot and come back to me if you get stuck.
( I do this for a living and all too happy to help.)
 

Danspeed1

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It took me a week to figure this out. Turns out gunk in my door lock switch was causing internal arcing which was leading to a short. I replaced the switches and it worked just as stated above.

Thanks,

Dan
 
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