directed 712t keyless unlock problem

I just installed a DEI 712T Keyless Entry Unit in my dad's 99 GMC Sierra. It was not previously equipped with power locks so I added a 2-wire actuator to each door (2 doors).

95% of it works: When I turn the ignition on, the doors lock correctly, when I turn the ignition off the doors unlock correctly, when I hit the lock on the keyfob the doors lock correctly, but when I hit the unlock on the keyfob the locks unlock for a nano-second and then lock again. If I pause and then hit the unlock on the keyfob a few times, eventually it will unlock but the number of tries is random and it definitely just unlocks and relocks always on the first try.

Since the ignition lock / unlock works correctly and randomly the unlock from the fob will work correctly I don't think it's a problem with the relay wiring. Could this just be a timing issue that is programming related that it's not sending the unlock from the keyfob long enough and the actuators aren't resting at the unlock position?

Anybody have any ideas what the problem could be and how to solve it? I'm completely stumped.

Thanks to anyone that can give me some advice.

Ralph

Is there a way to extend the lock pulse? Most likely there is, try that an see what happens! It will be in the programmig features!

What i've noticed with adding on actuators is that the sometimes the actuators that have the longer run from the relays tend to receive the current last (barely noticeable you have to observe carefully), this being the case they also recieve the shortest pulse, which may result in them not opening fully, and returning to a closed state, i just used a longer pulse from the unit and cured my problems when i encountered this particular problem!

However, this is my experience, your problem may or may not be of this nature!

Oddly enough I can't get the 712T into programming mode for some reason. I've tried about 6 or 8 times. I can get into the keyfob programming mode by hitting the valet/program switch while the ignition is on and I've confirmed I can learn and unlearn the remotes, but if I try the ignition on/off and then hit the valet button I can only enable valet mode, it never goes into the programming mode like the manual describes.

It appears I want feature #4 in the programming options and I want to turn it off to get the 3.5s lock/unlock pulse instead of the default .8s pulse, but I must be a complete idiot because for the life of me I can't get it into programming mode following the instructions.

I'm at a loss as to what to try next. It's pretty sad that I've installed multiple alarms and remote start systems in the past without any problems on any vehicle and a stupid keyless entry system is causing me more grief than anything.

They're only being used with the 712T and nothing else. The 712T has the relays built in, so everything is done by it. From the 712T the 2 actuator wires are going to the actuators in both doors directly, no additional relays or switches or other lock control devices in the path.

Thanks

Ralph