The Central Timer Module is something totally different, it's by the steering column.
The "SCTM" is under the front center "seat".
There is a harness from each front seat back that runs to the center seat, to the SCTM.
The module will disengage the lock from the seat belt reel, so it can be pulled out/reeled out , and than back in after your done buckling up.
The module fails in such a way that it keeps the solenoids powered, so you can reel out the belts.
When the solenoids are not powered, the reel for the belts stay locked.
From my measurements, the solenoid in each seat draws about .21amps.
If you look under the front center seat, there is a small black box on a bracket, on the underside of the bottom seat.
If you pull the connector from it, you than wont be able to pull the belts out of the seat back.
If you pull the fuse 12 , (on my 99) it kills the drain as well.
The other way others test it, is leave the windows open on the drivers and passenger side, close the doors of the truck, leave the truck sit for over 30 minutes.
Do not open a door, just reach in, and see of you can pull the belt out of the seat back (ether driver or passenger).
You should not be able to... the reel for each belt should be locked. If you can still pull them out, than the solenoids are still powered (unlocking the reels) and draining the battery.
PS:
The links inserted onto this post are not something I did, and mean nothing, not sure why the forum but such links on the word solenoid.
EDIT: seems the links are gone now, strange stuff,,,,