Hello, we have a 21 ft dual axel travel trailer. Last winter we had our 7-way plug get corroded. What brought the corroded plug to our attention was that the brake controller inside the truck had the green light lit up when the trailer was not connected. My husband said that probably snow, salt or whatever got into the plug that caused the light to go on. Sure enough when he removed the plug a few months ago, we had a corroded plug. My husband replaced the 7-way plug and we are now having the trailer brakes lock up for about 10 feet and then release when we try to pull out of our driveway. It only seems to be the brake on the passenger side rear wheel. Previous to the replacement plug we did not have any problems. Any ideas as to what could be causing the rear wheel to lock. Do you think we have a bad new 7-way plug? We have not been able to use it this summer and now that it is fall, we are stating our field trial season and need to live in it for the next few weekends. Thanx in advance.