How the DeLorean's Power Locks Work.

["Jim Reeve" <ultra@xxxx>]

Ok everyone, since not everyone is clear on the function of the power 
locks, here is a detailed explanation.

The locks in the DeLorean are not the typical power lock system. It 
is what is known as a Central Locking System. What this means is that 
when one door is locked/unlocked, the other door(s) do the same. 
There are no extrernal button switches, as they are built into the 
lock mechanics inside the door.

To my knoledge, this was a fairly popular fad in the '80s, but there 
were reports of people being carjacked/robbed when someone would hide 
on the other side of the car, and attack the driver when he/she 
unlocked thier own door.

The lock controller on the DeLorean uses a negative pulse to trigger 
the locks. Manually locking/unlocking one door from either the inside 
or out, will throw the internal switch, giving ground to the common 
sense wire that goes to the controller and other door switch. (Also in 
the case of the "Lock Doors" light the ground here will be powered 
when unlocked, and when the inertia switch is tripped the ground to 
the fuel pump is simply redirected to the unlock sence wire.)

If your doors will power lock in one direction, but not the other, it 
may be an indication of a previous failure by the stock module, 
causeing the solenoid coils for that direction to burn out. However, 
this may not always be the case. When I bought my car, both doors 
would lock, but only the manual one would unlock. After unplugging 
the connector (the 8-wire harness) and plugging it back in, everything 
worked normal.

And it is also VERY easy to tell if you have a Lockzilla or original 
module. Open up your relay compartment behind the passenger seat, and 
look at the black box right in the middle, on top of everything else. 
If it says "Lockzilla" on it, there you go. If it is unlabled, it is 
original. While your in there, you should also permenently remove 
your fuse box cover and check the condition/connection of all fuses.

This winter, I removed my lock module and opened it up. The part that 
commonly fails are the two internal PC-board relays that can stick 
closed from the power surge created by the solenoids. I was able to 
find a new, identical PC-board relays. Only these were rated a little 
more heavy duty than the originals (40A, I'm pretty sure the originals 
were 30A). I removed the old relays and soldered the new ones in. I 
have been using my stock module in this manner all of this year, 
without a single problem yet. This modification is NOT for most 
people though, and I'm not going to be using it like this forever. I 
would strongly recommend the Lockzilla to everyone, and I will 
eventually get one myself. The primary reason I did this was because 
I wanted semi-safer working power locks, on a tight buget. (Total cost 
was about $15.) I do plan on putting indicator lights inside the car 
that will light up whenever a solenoid is getting power, so I can 
actively monitor if one of the new relays I put in has failed.

I personally am sceptical of the locks "locking on thier own", but I 
do have a theory that in a moderate/severe shock to the car, the 
internal switch inside the door could bounce just enough to trigger 
the lock module.

If anyone has any other questions about the locking system or about my 
modification, please email me directly at ultra(at)isd.net. Take 
care.

Jim Reeve
MNDMC - Minnesota DeLorean Club
DMC-6960