I'm trying to find the right wire to test to find if the duty solenoid is stuck on, since my Legacy seems to have the AWD "on"all the time except when the ignition is off. I can't seem to find a wiring diagram that shows which wire to check for the duty solenoid. Any help will be appreciated thanks.

Don't you have to put a fuse in a fuse slot in order to turn OFF the AWD action, or is that with older models?

If the solenoid were stuck "on" I'm pretty sure you would have no awd. This is why almost every time they fail it gets locked. The solenoid opens the clutch. The most likely answer is that the solenoid went bad. I'm unsure if there is any test with a multimeter to confirm but I'm very far from an electrics expert. You can however put in the fwd fuse anf see if the problem persists. If still in awd with the fuse in its probably the solenoid.

Right the duty c bleeds pressure off the transfer clutch, so if it is not energized it will be stuck in AWD. It's not really an on/off control, the TCU uses a 50Hz square wave and varies the duty cycle between 5% and 95%. Does the ATF temp light flash at all on startup? Do all your tires match? Was the trans replaced or anything? It could just be good old fashioned torque bind. For various reasons the transfer clutch plates can wear groves into the drum and then they stick or get stuck in there and it causes torque bind.

The reason I needed to test and see which wire supplies power to the duty solenoid is because I replaced a 1991 transmission from a 2.2 engine with one from a 1997 2.5 engine and the wire harness ( although plugs in) is different and not supplying any power to the duty solenoid, as far as I can tell. Putting the fuse in changes nothing since the harness is not wired correctly. It shifts fine and everything else works except the duty solenoid, as I can tell by the binding on turns that disappears if the ignition is turned off ( meaning the clutches are not stuck in manually)  As I see it I have two options

 1) wire the harness correctly,(the right wire from the TCU going to the right one that goes to the solenoid)  except I can't find diagrams that I can make since of, because Subaru changed colors and order in this harness almost every year.

2) wire a switch in to give power to the duty solenoid so when I don't need AWD I can switch it on.

 Since I use this car on a mail route every day and our snow is melting,any wiring diagram suggestions or help will be greatly appreciated.

Ah ok got it, not sure if this is helpful I found this piece of diagram labeled 97 awd solenoid: But the only wires showing colors seem to be on the harness side which is probably the 97 harness in this pic so it might not be good.

Edited January 26, 201610 yr by porcupine73

Thanks, now I just have to make sure the wire on the '91 (engine side) connects to that wire on the '97 (trans. side). I think it's a brown wire on the '91 engine side. I'll let you know what happens, but thank you!