I still think you're having vacuum issues Ryan. Best bet would be to start with the vacuum "ball" canister that usually mounts behind the front bumper on the pass. side. Wherever you have that now (since you're running a winch bumper now) test it to ensure it's holding vacuum. Fire up the jeep, shut it off, then pull the hose connector off the side of the canister and it should "psssshhhh" air. if not, then you've got a leak somewhere between the engine vacuum source and the canister. Those plastic lines get brittle so it'll take some time and detail to look it all over.
I had one XJ that had a hair-line crack in the back plastic line that runs along the pass. inner fender down to the canister. Checked it several times but removed it entirely to replace it with another known good one I'd pulled off another XJ. The old one had a hair-line crack down near where it ran close to the battery.
Definitely look at the operation of your heat control valve that's in line with the heater hoses under the hood. With the engine running, note the position of the arm coming from the vacuum actuator. Then turn the heat on and then go check the position of the arm. It should have moved, opening the valve. If it's not, then check the actuator - take a length of vacuum hose and connect it to the vaccum port. Suck on the hose and see if the actuator moves. Hold the vacuum and ensure that it doesn't leak down (actuator arm moves in, then slowly moves out as you hold the vacuum).
Last thing to check would be the vacuum bulkhead connector on the back of the heater/AC control panel. These become problematic when they dry out, or if someone has done some stereo installation or other work in that dash area and either damaged the vacuum lines going into the bulkhead, or the bulkhead has come disconnected from the switch panel.
Another thing to check to be certain it's not an electrical issue...... turn the A/C on and ensure the compressor clutch is engaged and the clutch face is turning. This will ensure the electrical switch on the dash control is working and your system has pressure. If the A/C compressor is turning, and you're not getting cold air, the blend doors aren't moving to allow the cold air to pass through the box.
The fact that you've said that you sometimes get heat when its set to heat, and sometimes get A/C when it's set to cold suggests to me that - again - the vacuum system isn't working properly and the blend doors aren't moving into the positions they should. Very indicitive of vacuum leaks.
