While he has given the complete items for us to help. HE LACKS JUST ONE SIMPLE ITEM. WHAT is his problem with the steps. He states they do not work properly. WHAT does that mean?
1. What happens when you run the chassis engine and open and close the door?
2. Are you taking the 12 volt measurement with a multimeter or a 12 volt test light?
3. You need to isolate the step 12 volts from the RV. Disconnect the 4 wires from the quick connect. Run just a simple 12 volt wire positive to the White and RED. Do not worry about the Yellow. Then take the Brown and put Ground to it and release. Continue doing this. The steps should operate. If NOT, then the control board is bad. Doug