On your "N" port is that a dual ported connection?
In that it has 2 possible connections, one on the side and one on the rear?
The way your drawing is it would seem to be a single port.
Power beyond connections can be a royal pain,
some power beyond connections will require a plug to be installed to divert flow out thru them while they are internally ported to the tank.
If you have two lines connected to the "N" port that would behave similar to having 2 lines connected to the pressure port.
"I need to go an see if I can identify the 3 hoses (originally) coming from the loader connected to the ports."
If your loader valve had 3 lines going to the block the "P" port should have been pressure to the loader,
the "N" port the power beyond port from the loader, and the "T" port the tank return from the loader.
If this was the case your installation becomes a bit more challenging.
Let's see if I can guess whats going on.
3 possibilities and different configurations.
Original
"P" goes to loader pressure port,
"T" from loader return to tank,
"N" from loader Power Beyond (likely to3pt)
NEW with Back Hoe
"P" goes to loader pressure port, (no change)
"T" from loader return to tank, (no change)
"N" not connected, piped to rear of tractor with a Quick Connect
Back Hoe pressure in from Loader Power Beyond (original "N" connection) now connected to quick connect for back hoe supply pressure.
Also a new line added to "T" with Quick Connect at rear of tractor for Back Hoe.
Back hoe is connected to 2 Quick Connects;
(1) Supply (pressure) from loader power beyond originally connected to "N"
(2) Return for Back Hoe connected to line and quick connect added to "T"
3 point does not work with back hoe connected
New with Back Hoe removed;
Install a jumper from Loader Power Beyond Quick Connect (used for Back Hoe Pressure in)
to
The Quick connect that was added to the "N" port.
The 3 point will now work.
This jumper must be installed when ever the back hoe is not hydraulically connected to the tractor or the hydraulics will be dead headed and over loaded.
I hope that this is not too confusing.
Good Luck
Lou