I have a wiring dilemma that I am looking for assistance on. I have a 2003 Itasca Horizon 39QD with a Atwood GCH10a-3e water heater. I had my tank freeze and rupture this winter. I purchased a Atwood Tank replacement kit (new bladder tank) part #93953. This is supposed to the direct tank replacement for my model water heater..The new tank has different wiring requirements than my original. The new tank has a relay in the 120v circuit that powers the heating element. This new relay requirements a yellow (I believe 12v ) wire from the control board. My control board does not have that wire. My original had the hot line from the 120v source route through a Eco T-stat (Electronic thermostat and cut off) then to the element, The new one has this relay in place of the t-stat. Any ideas on how to make the new unit work?