About to pull the engine on my 90 civic hatch and I have one electrical connection that I can't undo.

I just can't figure out how to disconnect this one. Also anyone know how to disconnect the shift linkage I did not see how to do it when I was under there.

Also I have never seen a drain plug like this one before.

How does this come off?

Thanks

 

That is the switch that turns the radiator fan on when the engine gets hot. Pull the rubber boot back then there is a plug for each wire (the wires can be swapped with no effect, so no need to remember which goes where).

Typically the engine is removed with manifolds and wiring still attached. Unplug the big harness connectors on either side and undo the white wires to the fuse box. You will need to disconnect and remove the alternator for clearance to swing the engine around on the way up.

The shift linkage is supposed to disconnect by driving out a pin in the shaft where it goes into the transmission-- but in practice it is often rusted in place. In that case disconnect the shift linkage at the bottom of the lever that goes inside the car and leave the linkage rod attached to the transmission.