Solved: 0.5a parasitic draw on IOD fuse 1998-2000 club cab only

[kevinb70]

Fixed this a while back so I figured I would post the fix here. The symptom is a 1/2 amp parasitic draw, which can kill the battery after a few days of sitting. I traced my parasitic draw to the IOD fuse.
And then I traced the draw to the seat belt retractor solenoids. They were powered 24/7 instead of going to sleep and locking after 30 minutes of key off and doors closed.
And then traced the issue to the door sense input on the driver door. There was a ground signal with doors shut.
I disconnected the electrical connector from the seatbelt control timer module (SCTM).
And probed the door sense wire. There should be neither a +12V nor a ground signal on the door sense wires. With the doors closed you need a 0L ( no connection) on your multimeter against ground and +12V.
Any signal will keep the SCTM awake and will keep the seat belt retractor solenoids powered up. This is your parasitic draw.
I've seen a lot of fixes on YouTube which completely disable the solenoids, which is unsafe when driving. Or replacing the SCTM which doesn't help if you have a ground signal coming thru the door sense wire. I bench tested my SCTM, and worked perfectly, going to sleep at exactly 30 minutes, and grounding a door sense input wakes the SCTM and triggers the outputs to activate the seatbelt release solenoids.
What I did was cut the yellow wire, which is the driver side door sense so that opening the driver door does not wake up the SCTM anymore.
So to get the seatbelts to retract easily, I just have to switch the Ignition to the on position and I can put on my seatbelts. When I have a spare weekend, I'll actually go back and trace the wiring and see where I can find a slight ground short on that wire I think it's in the door threshold because it gets the wires get kind of mashed up over the years. So I'm going to be starting there whenever I have time.

[maxwedge]

Impressive! Good job.