There are two schools of thought. Number one is that there is a leak, number two is that the latch mechanism is stiff. The pump has safeties and will disable a door or trunk if it can not sucessfully perform a latch in two tries. I am on my second pump and they never found a leak. Some people have tried modyfing the safety, I have pondered adjusting the latch so it latches before hitting the pressure safety. It is working and untill I have isues wont do anything. If the fuse trick works you can get some extra use, but as I found out once it stars the others will act up.