Help fixing a Code Alarm security system

My Code Alarm car security system just died. I can still lock all doors

with the keyless remote but, the remote can't be used to unlock the
doors. I can hear a click noise from under the dash (drivers side) but,

it won't unlock the doors. I tried using a spare set of keyless remotes

but still same result. At this time entry is only gained by using the
key in the door. When parking the truck, usually the doors
automatically unlock when turning the ignition off, now the doors
remain locked. You can still hear the weak click noise under the dash
when you turn off the ignition. But, you must manually unlock the door
to get out.

I bought the car used and it had an aftermarket security system install

in it already. No alarm, just a keyless entry system and an ignition
switch cut out and a red led flashing light on the dash.

Can anyone offer me any tips/suggestions on how to fix this?

A very good site to help is http://the12volt.com/ . Not sure what type
of vehicle you have so no one can give you the correct info. Many cars
have a dedicated line for the locking action and a second line for the
unlocking action. When the line recieves a momentary ground, the doors
lock or unlock. It is possible that the joint has come loose. So you
would have to look at the code alarm box under the dash and follow
where the unlock wire goes and check the connection. The wires should
be labeled on the side of the case on the code alarm to where they go.
If you find this wire, you can touch it with a ground and it should
unlock that will tell you everything in the car is working. and perhaps
the code alarm module is bad.

Chryslers and some other vehicles use the same wire for locking and
unlocking. It works off of resistance. If you touch the wire with
something like 250 ohms, it locks and with 800 ohms, it unlocks...so if
that is the case one of the resistors is bad.

I would post your question at the12volt.com and be sure to provide the
make and model of vehicle.

umpqua123 wrote:
> Thanks for the advice. the12volt.com is an awesome site!
>
> BTW. It's a 96 Toyota T100 2dr truck with manual locks and aftermarket
> actuators installed.

My first inclination is that the installer used a relay set to operate
the actuators, and a contact in it has failed. The unlock wire could
have an open anywhere between the alarm module and the relay set as
well. Finally, it's not impossible to fathom that both actuators
failed at nearly the same time. They are typically pieces of crap.
Look at the price for a set of 4 new aftermarket actuators and you will
understand how junky they must be.

Toyota MDT in MO

You were right! I opened up the unlock door relay and found an eroded
contact that still clicked for a momentary contact but insufficient to
signal the actuators to unlock the door. I found a new relay at a car
stereo/alarm place for $3 and all is well. Thanks for your help.