having issues with keyless entry

Hello. I have a 1987 Toyota Supra that the previous owner installed a Hornet 563T alarm system in. I have been having issues lately with the keyless entry system. When the car is locked, and I hit the button to unlock, the car unlocks just fine. When I try to lock the doors at this point, however, the lights flash but the doors dont lock. I also tryed locking the door from the inside and closing the door but as soon as the door closes the door unlocks. THe only way to lock the door is wht the actual key. Every other part of the system is working just fine with exception of the doors locking. Where do you guys think I should start looking.

Does using the key in the door of your Supra lock and unlock both doors? If that's the case one possibility is that the previous owner used the wires to the doorlock switch on the door panel, whereas they should have used the wires to the key cylinder.C Renner's Auto Electronix

My service is cheap, quick, and good - pick any two

Yes, when the door is unlocked/locked with the key it does both doors. So what I should do is pull the door panel and see where the wires go?

I would imagine that the wires from the Hornet are connected in the driver's kick panel. Check out where they are connected - and meter the wires to see if they go to ground when the switch is pressed or when the key is turned in the door. Also, here's wiring info to guide you if you don't have it already.C Renner's Auto Electronix

My service is cheap, quick, and good - pick any two