I removed the OD, and replaced a few things in it (o-rings)..put it back in and now all the sudden it doesn't work.

The LIGHT on the dash does come on, but nothing happens. I havent as of yet checked to hear if the relay clicks or not (I just found this out, and I'm too tired to work on it right now).

Is it possible to wire it backwards?

Am I thinking of AW-70 solenoid or Laycock DeNormanville when imagining the O-ring replacement? If you have the M-46, I think just like the speed sensor in the rear axle differential for later cars, the solenoid is not sensitive to polarity.
--
Art Benstein near Baltimore

"Everybody's got to believe in something. I believe I'll have another beer." (W. C. Fields)

I replaced the O-rings on the pistons (?) that control the on/off function of the OD. I know that when this OD was sometimes working a few years ago, Duane suggested new O-rings on them.

The solenoid worked fine before I did this, and I had refurbished the solenoid already (I have two now actually).

I'm sorry I left this information out, I was about 3 minutes from falling asleep when I posted it.

Automatic transmission or manual/stick shift?

I only have knowledge of the automatic OD, but if you had a working system before your o-ring replacement and now do not, you may have knocked dirt down into the tiny holes which pass fluid and allow the OD to engage. Or, your o-rings could have slipped during installation and now are blocking the ports, or letting fluid squirt out (check for this).

Your comment about refurbishing the solenoid however makes me think you have a manual, because I have no idea in what way the average home mechanic would refurbish the automatic OD solenoid.