Chrysler Repair: Chrysler 300m door locks, loud buzz, mechanical switches

Question
i have a chrylser 300m 1999- everytime i go to lock the doors- it makes a loud buzz sound on the front passenger and driver side doors- very loud and sometimes the locks stick.. Any advice on how to fix it?? Thanks!!!

Answer
Hi Kristin,
There are three electrically operated mechanical switches (called relays) located in the fuse/relay box on the lower left corner of the dash (on the driver's side of the car). So find that box (also called the junction block) where you will find  a number of fuses and 9 relays (small square boxes that are plugged into the box). The three that operate the door locks are number 7,8,9 and may also be labelled at to that purpose. I would begin by noting whether the part number on each relay is or is not identical to one of the other two relays. Then I would try exchanging the positions of those relays which are identically numbered. Then try the door lock functionning again. See if the problem is solved or alternatively modified so that the noise has moved its location. That would suggest that one of those relays is faulty. So I would then get a replacement relay and try substituting for one or the other relay (or if all 3 have the same part number then try putting the new one in place of each of the 3 to see which one, when substituted, results in a cure to the problem). The relays are simply pulled out to remove.
So try the relay substitution approach and let me know how it works out.
Before you do the relay approach, I would also try to operate the locks from the passenger side door to see if the problem is indentical. If not, then that would suggest (but not prove) that there is something wrong with the electrical switch in the door lock mechanism of the driver's side door lock. So go ahead and do the relay switching test and then we'll sort it out.
Roland