DO NOT stand between the MH and trailer unless you are positive hubby knows you are there and the MH is fully stopped. Crazy accidents happen!
Stand where he can see you in the driver's side mirror. You turn facing the hitch, close to but not behind the MH bumper. between Set up a system of hand signals.
YOUR HAND straight up means STOP. IMMEDIATELY.
Your hand pushing towards you means he needs to move the rear of the MH left, away from you means he needs to move right. Stop him, and check as needed.
First thing is to get lined up and straight with the ball.
Then get the distance right.
Hold your hands vertically in front of you to indicate the distance. Move them together as he gets closer. Stop him as needed for you to step forward and check.
It will take several steps especially if he can't see what he's doing at all.
A better camera, and some clear markers on the ball & MH, would be a big help getting lined up, although he will need some help on distance.
If you can get it done in 4-5 increments that's pretty good.
