Car Alarms: aftermarket power door locks, chevy astro van, power door locks

Question
QUESTION: In 2004 I purchased a new Chevy Astro Van which happened to have an aftermarket (not GM) door lock system installed.  Recently all locks on this system failed to operate.  I have been very frustrated in finding any information to help me diagnose and repair the failure.  I can't even positively identify fuses or relays (if any) associated with the lock system.  Nor, have I found what appears to be a power door module.  From what I can tell, the system "looks" like what a company called "Commando" markets, but I can't be sure.  Can anyone offer some help?

ANSWER: Well, not the easiest thing, but to do service
on this you'd need to expose all wires, and fusable
links to check for blow outs all the way
from the inside of the door at the actuators,
to the relays and outputs on the alarm.

Door locks kits are fairly universal in design.
These require a set of relays and a control
unit. The relays may be hidden in central box,
but all are conected to a power source.

You will need to inspect all connections and power
points for the troubled relay or fuse.

Command Car Alarm is a reseller, and so am I. These
are made over seas and need positive triggers to
operate them. To replace them is easy if need be.

Trace, locate and repair & or, replace is suggested.

ALARMTEK

---------- FOLLOW-UP ----------

QUESTION: First of all, thanks much for the quick response. I'm impressed!  But, my frustration still remains as I can't seem to locate a central control box.  I see nothing added under the dash.  I find it unlikely that it would be located within the driver side door panel.  Do you agree?  There is, however, a fuse and two (SPDT) relays (with unused 87a contacts) in the van's interior fuse block.  In the van's owner manual, the fuse and one of the relays is are identified as being associated with the van's power locks.  (Again, the van was not equipped with factory locks).  The relay and fuse seem OK.  Are there additional fuses and/or relays somewhere?  Finally, is there any way to obtain a circuit diagram for a typical aftermarket power lock system as installed in a vehicle similar to mine?  Thanks in advance for any additional help you might provide.

Answer
Almost shut down for the evening.
Ok, you found the lock and unlock relays.
Good, then no need to search out a central door lock box.
These actuators are being powered by those relays.

See 2 of my pages to review:

www.KEYLESSCAR.com
www.RELAYHELP.com

I hope this helps you nail it.

Nite.

A