1997 Gmc Yuko GT electrical problems

I have a 1997 GMC Yukon GT that has 81,000 miles on it. I purchased it in 1999 with 30,000. As of late I have been having alot of electrical problems. My remote for the door locks stopped working 1 yr ago, and since then when I am driving down the road, sometimes my door locks will just start locking and unlocking. Also, If I let it sit for a couple of days, it will be dead. I have replaced the alternator, battery and the door lock relay to no avail. The dash was also acting up. My mechanic fixed the dash, but was unable to fix the locks, and the battery draining problem. My mechanic rewired the locks and it still dies after a couple of days. Any suggestions, I am getting desperate.