It's a 98

 

I'm going to go out and look again when it's dark. There has to be a little light somewhere I'm missing, I just can't find it.

 

Page 8W-12-12 in the 98 FSM shows everything on the IOD fuse. One of them is likely your candidate for your draw.

 

I see a seat belt control module. That's now my top culprit. I replaced my driver seats with one out of another truck. After that I started getting a seat belt chime. I assumed because the seat was from a different cab configuration. Only problem is this swap happened at least several months before the battery issue. I'll investigate anyway.

 

For some reason I couldn't figure out my volt meter today. I *thought* I had it all setup the same as the first time, but I couldn't get ANYTHING to register amp draw, much less specifically what I was working on. But the truck started (barely) as I've had the iod fuse pulled since I last drove it. So either I'm an idiot or something is wrong wit my meter. Which I think the meter is fine, It tested voltage without issue.

 

I think most meters are only rated for a couple amps draw thru the meter.... any more than that, and it blows a fuse, or smokes the meter......

 

I think it's ten amps and for a specific period of time. Before it blows. I would only touch it for a brief second. But, if it was fried I wouldn't have been able to use it for measuring voltage. I'm 75% sure it's user error.

 

Check the fuse in the DVM, it only protects the current measurement circuit. At least on mine everything else still worked after I made an error in judgement ...

 

Take a good look at the SCTM and the seat belt solenoids. My dads 98 had a draw that would kill the battery much faster than it should. One day I opened the door and heard some noises coming from the driver seat, it shut up when I unplugged the wire going to the seat belt solenoid. On the 98 it had a SCTM that applies power to the seat belt solenoid to unlock it when the door is opened or the key is on. I seem to remember something about a steel ball that makes contact when you hit the brakes or roll the truck past a certain angle and it locks the belts and sometimes that ball gets stuck. It's around .5 amps when the SCTM is doing its thing and the extra amps when you open the door are probably from the interior lights coming on. You can also check for 50-60 ohms across the terminals on the seat belt solenoids to see if one is bad.