Electrical lock system not working properly. Key will only unlock single door which its being used on. Door lock switch does not unlock any doors - No odd noise heard. Fuse box No. 14 - 20A fuse is not blown. Here is the fun part. When fuse is reseated the electrical lock system will work - Key will unlock all doors - door switch will unlock and lock all doors. Then after about 4 or 5 tests the system stops working. Re-seat fuse then works for another 4 or 5 tests. Where should I start. I feel its at the fuse box - maybe a loose connection somewhere. Did not find a diagram that I could trace or figure out the wiring for the locking system from the fuse box. Much Thanks