97 tahoe avistart 3200 door lock problem

I borrowed my friend's '97 Tahoe last weekend to tow a vehicle that I bought. This Tahoe has had a Avistart 3200 installed for 3-4 years with not issues. The vehicle did not have an electric brake controller, so I had that installed before I left (not at the same shop that did the remote start). This installation was less than to be desired....wire through firewall with no grommet....poor mounting in rear...wire in rear connector feeding 12v back into reverse lights....etc.). I fixed all of these issues that I had found before I left on my trip. The vehicle performed fine for the entire weekend. Three days after the electric brake controller install, I use the remote start. It worked just fine. Since then, the power locks have stopped working, both at the switch and with the fob. The battery is also draining. I have determined a couple of things. A. the system is ALWAYS trying to lock, which is what is draining the battery (as if you held the lock button down). B. when I unhook the lock/unlock outputs from the remote start the factory door locks (at the switch) work as they should. The two lock/unlock leads from the Avistart unit (green and blue) appear to be just fine, with no ground outs or breaks. The blue wire is connected to the light blue wire at the vehicle's lock relay, and the green goes to white. Obviously the system can't be hooked up too wrong, or the system would have failed years ago. Is this likely a failed Avistart unit? Do they fail in such a way? I am not an installer, although I have some 12v experience. I have a meter, so I can test anything that is suggested. Thank you, Reggie

Some added info: The blue lock output wire ((-)unlock, (+) lock) is providing constant 12v+ with the ignition off. Also, the vehicle has been set up to lock when you put it in gear. I am not sure if this is a function of the Avistart unit or the vehicle's internal system. This function is not currently working, even with the Avistart lock leads disconnected. Could there be a relay/switch stuck in the closed position upstream of the DEI unit? Perhaps the one that is supposed to lock the doors when the truck is put in gear? again, thanks for any help! Reggie

I have this same prob with my 01 Suburban. I can hear the Avistart trying to lock/unlock my doors and the OEM door lock switch dont work. They work as designed when I disconnect the power door lock switch wires from the alarm brain. I took it in from where I had it done and they said I have a bad alarm brain and need a new one. Unit is only 2 years old or so. The alarm works fine, autostart, etc. but except for the lock/unlock using the keyless of the alarm fob. Cant I just use a relay and the negative output trigger from the alarm to lock/unlock the car locks?

WOW!! It took DEI 2 MONTHS to send me a new unit under their "lifetime warranty".....or as was pointed out to me "limited lifetime warranty", which means I had to BUY a replacement unit for $45.00. They sent me an Avistart 4200 to replace the 3200. I guess its nice that they sent an updated version, but one of the harness connection doesn't match up. They included all new harnesses, BUT A. I was hoping for a plug-n-play replacement, and B. THE HARNESS I NEED SEEMS TO BE THE WRONG VERSION. To top it all off, DEI OVERCHARGED MY CREDIT CARD!! What a joke of a company (I've currently been on the phone for 25 minutes trying to solve this problem). I am completely disappointed, and will make a point to never buy a product made by this comapny if I can help it.