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aftermarket keyless

cruiser54

NAXJA Forum User
Location
Prescott, Az
I've searched but gotten no definitive answers. My 88 Laredo has power locks and I performed Greg Smith's fix on them. I purchased an aftermarket keyless remote set-up but it won't work cuz the locks use a reversing polarity system. I've looked at the original factory keyless entry wiring diagram to no avail. I read somewhere that I could use a "5 wire" relay mod to get them to work. Anybody had any success getting one of these remote systems to work?
 
I stared at the wiring diagram a bit. Assuming that your alarm has outputs that go to ground to trigger relays, then yes the "5 Wire Alternating 12 Volts Positive Door Locks" on that page would be the easiest to implement. You need to locate the two wires going to any of the lock motors, and wire in the relays as shown.

As a quick test with a meter, you should see that both wires to the lock motor are normally grounded if you're not hitting any of the switches. When you hit unlock, one of the wires will get connected to +12volts instead. Locking should apply power to the other wire. The 5-wire relay setup does the same thing. Normally, the relays are just connecting the wires straight thru. When triggered, it breaks the connection on one of the motor wires and connects it to +12volts instead.
 
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If the alarm has outputs that apply 12-volts to trigger relays, you'd need to modify the diagram a bit and ground the pin 85 instead of connecting it to the fused +12volts.
 
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