Jeep Repair: Draining the Radiator, coolant temperature sensor, coolant temp

Question
I am trying to replace the coolant temperature sensor, and everything I have read says to partially drain the coolant. Well, I turn the the little lever at the bottom of the radiator, then remove the cap at the top of the radiator, and nothing happens. I have a '98 Grand Cherokee with the 5.2L engine. I figured that the hole was clogged. The only thing I could find to stick up the little is a pipe cleaner, and that gave no evidence of a clog. Any Ideas?

Answer
Factory drain plugs for the radiators are horrible.  I've probably had to replace a dozen or more in the last 2 years by attempting to use them in their designed manor.  At this point I would say run it back in and don't mess with it any more.  More importantly, watch for drips in the future because the o-ring on the plug may have been torn.  It's a poor design and the only ones I really "enjoy" are the screw kind.  The twist and pull like on yours are junk.

Back to the problem at hand.  The Coolant temp sensor is burried down behind the altenator.  Your best bet here is to just go ahead and unplug it and remove it with a deep socket.  You are going to spill coolant but if you move quick enough you won't have too much loss.  Put the other back in as quickly as you can and tighten it down.  After you're down hose down the engine (try not to spray too much in to the altenator and distributor).  Let it drip dry if at all possible.  You should be good to go after that.  

Of course, don't do this with it hot or else all that pressure will come out at you.

Some 5.2/5.9L have a second coolant temp sensor located next to the primary one.  I think this is just the dummy light but they are real sensative so try not to hit it.
Doug