Door ajar dash light staying on

Got to work this morning and went to lock my car and it did the beeping thing indicating a door is open. Checked all the doors, and rear hatch ( it's a omega sportswagon). They were all closed. Noticed like a strong electrical burning smell and was pretty sure I narrowed it down to the 'actuator' I think it's called in the rear hatch door. Got a new one from wreckers and replaced it. Thought was all good and the light was off till I was driving home and it came back on. I dunno what to do? I can't lock it because when I do, everything does lock but the alarm goes off about 10 mins later. Any suggestions would be great. Thanks
Dillon