77,
Hardwiring your ScreenLogic is just asking for trouble.. All it takes is a nearby lightning strike and your system will be toast and everything connected to the Protocol adapter.. Ask me how I know that...
I should have said to turn off the power to the EasyTouch when you removed or installed J20. Obviously, you have to have power to the EasyTouch when you are testing for the 15 VDC..
Chips can go bad when the RS-485 connectors are removed or installed with power on, or wires are connected or disconnected with power on..
The first step in troubleshooting an RS-485 issue, with an EasyTouch, is to Remove EVERYTHING from J20 except an IntelliFlo pump.. Then fire things up and go look at the pump. It should show "Display Not Active" when in AUTO... This means that the com port is controlling the pump. If your pump does not show "Display not Active", it normally means the RS-485 chip on the main card is bad (95%) or the chips in the pump are bad (5%).
One problem with the RS-485 com port is that any device failure can lock up the entire bus and nothing works..
Thanks,
Jim R.