Picked up an 01 3500 the other day and was doing ball joints on it today and slid under it and saw this . Top plug for the nsbu what is the function of the wire that's broke ? Obviously someone has been in there. Can I buy just that plug ? There's not enough sticking out to get a good bite on to repair it. Only symptoms I have noticed was a slight harsh downshift. But, have not put many miles on it thanks guys Matt .