NIce ME310 motors keep fusing

[Andre007]

Hi, can someone please help. I have replaced x2 Nice ME310 motors a year ago and all been working fine until recently. They seem to be ok when the weather is dry but as soon as there is moisture in the air or rain they fuse in a particular position. The connections to the main junction box are dry so sure this is not the problem. I have unbolted the motors and looked at the bottom of the units and there does seem to be alittle corrosion, but I have put this down to them sitting in water in the ground from time to time when there is a downpour. I have submerged one of the boxes in water and the system did fuse. But now all has dryed out... it's still fusing. They do fuse the main house not just within the junction box but struggling to know whether the motors have penetrated water or it is something else. They are both only a year old! Any ideas?

Any help would be great or tests.

Thanks in advance