just an update: we have a 16,000 lb 5th wheel. I had the brake controller set to light electric as I did not know you could change the setting. everything I read said that with that weight the controller should be set to heavy electric so I changed it. it's worse than light electric. you cannot lock the trailer wheels on heavy electric even with the gain set to 10! you could with light electric. so I went to a dealer and he said to bring the truck and trailer in and they will evaluate the situation. said it could be any number of things (controller module, software flash, trailer brakes themselves, antilock brake system). i'm really confused. don't the trailer brakes simply so a voltage on the wire and pull the magnets in based upon what that voltage is? i tried to ask the dealer how the various controller options vary this voltage and the service writer couldn't tell me. so i will ask the 'expert' when it bring the truck and trailer in next week.
2015 cardinal model 3825fl
2015 dodge ram 3500 dually