remote start is killing battery on my truck

I had a remote start unit installed in my 99 Silverado in January an ever since I have been plagued by battery issues.If the truck sits any more than a couple of days without being used the battery will most likely be dead and even when I'm driving it every day back and forth to work within 2-3 weeks the battery will go dead.I installed a new alternator hoping it would cure the problem but alas no as I am still dealing with battery drain,and this is even after I had a new remote start module installed figuring the original may have been faulty.

The only other option that the service technician where it was installed offered was to change the wiring harness for the module but I can't see how that would affect anything unless when it was first installed a wrong connection was made.

I even verified that the cause of the drain was the remote start system as I pulled the 2 fuses out of the original module and drove the truck for about a month and a half with no type of battery problems at all.I hate to just remove the system all together as it was a Christmas present from my finance but I've just about had it with the dead batteries.The remote start brand is Autostart which is supposed to be one of the better ones and we were told they have had "great luck with them".
Anyone have any insight as to what the problem may be?

clean your battery cables. make shure you have all the grounds from the battery to frame, fire wall and motor. next check your battery you may have a dead cell.

As said check charging and battery and battery amp draw.
If the remote start is drawing amps key off.
Take it off and drop it in the trash can.
MT

I have had new batteries all along including the one in the truck now which is only about 3 weeks old and every time the truck sits for too long without being started it will go dead.The drain has ruined 2 batteries,replaced under warranty thankfully.I measured the draw at 1.5 amps engine off and I'm not sure if that's common or not.I don't have any aftermarket stereo/amp draw,the truck is stock other than the remote start.The connections are so fucking clean from being taken on and off it isn't funny and yes they are tight.If anyone takes the time to read my original post you'll see that as long as the r-s module doesn't have any power going to it (fuses pulled) the battery will stay up.

Any more thoughts?

you do know there are two ends to a battery cable.

the box the remote start came in should say how many amps it should draw. i would not think any thing over .5 amp