Double Lock Control Unit

[shanghai_stin]

I posted this in the general maintainence forum, which had no replies

Thought give it a try here

I was checking the fuse box the other day, and accidently found there was a lose connector hanging beside the fuse box. and I took a look inside, found it fits into a box says "double lock control unit". so i plugged it in. suprise suprise after the weekend, my battery drained to the end (it's a new battery about 3 month old). not even a dash light can turn on. jump started it and then think, all that changed is the double lock control unit. (head light on auto, so couldn't be that).

Anyone knows what does this "double lock control unit" actually do? I can still lock my car without connecting it, and pressing the lock botton twice still disables the motion sensor. And how can a locking control unit drain the battery that bad? (I mean even the headlight was left on overnight, the dash will still light up.)

Thank you.