Ground HELP!

So got a little ground and I'm not sure where to go from here. Background: have an alarm system installed by monkeys and electrical tape (came with the truck). It started draining the battery when I enabled it so I stopped using it until I could figure it out. The alarm "speaker" or "alarm" would sound very weakly when enabling or disabling or if it was tripped.

Lately I just finished a front end rebuild (timing belt, water pump, etc...) and installed a GM alternator. Now I have a constant ground and the alarm system still sounds weakly and pathetically.

Some steps taken so far:

Prep: removed all the in line fuses installed with the alarm system wiring. Still had an amp draw.

Step one: Measured amp draw and pulled fuses to locate circuit
The amp draw isn't constant; it fluctuates between ~2 and ~.8 amps. So I started pulling fuses and pulling the ALT-S fuse in the engine bay fuse box cut the amp draw to .001. Ok!

Step two: Pulled alternator and tested for grounds: NONE. Checked alt pigtail wiring for proper wiring and grounds: NONE. Checked the stock pig tail wiring and sure enough there was a ground.

Step Three: Investigate ground. There was a measurable ground between the positive battery terminal and ground point but pulling or replacing the ALT-S fuse didn't affect this ground. So I started pulling more fuses and pulling the DOME fuse removed the ground.

Step Four: Pulled all dome bulbs and investigated for a ground: all good. Ground unaffected.

Step Five: Figured the ground was in the DOME circuit but that didn't make sense as the load was coming from the ALT-S circuit. So put it all back together and hooked everything back up except the neg terminal and checked for an amp draw again. Found it. Pulled the DOME fuse and amp draw wasn't affected. Pulled the ALT-S fuse and draw went down again.

So to sum it up as best as I can, I have an AMP draw from the ALT-S circuit and ground from the DOME circuit. Pulling the DOME fuse doesn't affect the AMP draw and pulling the ALT-S fuse doesn't affect the ground.

 

I know electricity is scary but I figured at least one person would have some insight

Further troubleshooting (I think I have it figured out):
Amp draw is only with the GM Alternator attached.

I hooked up my old (stock) Alternator and no amp draw. Now the GM alt works, charges, etc... and there is no ground fault across the prongs. I will take it to a local shop to look it over