Nissan Repair: J30 shifting erratically when it rains, transmission flush, filter change

Question
I have a 93 J30 with 195,000 miles that I just had a transmission flush and filter change done on and since then, it doesnt like to shift til well past 5-6k rpm after it rains. If it's been dry for a day, it acts normally. Then once it rains again, the problem arrises. I havent been able to go to the shop that did the flush yet because of my job hours. I'm just seeing if this could be something they did or if it's a common issue after 195k miles

Answer
Brandon,

The computer connection to the transmission is under the car and there is a possibility, with the age and miles, the connector could not be sealed and will need to be corrected.  If the shop had to gain access to the pan there is a good possibility that it happened then.  But, you really can't blame them since the harness is brittle.  I would get it on a lift and check out the harness and connections to the transmission.