jeepin4fun97

Rear defrost won't work... Switch light comes on but don't defrost rear window

Bigclubs

Well the light comes on, so I assume the fuse is not blow. Next place I would look is at he thin wires across the rear window, on old time vehicles( wires were on the inside of the glass), folks would break a wire cleaning the rear glass. There is a silver repair liquid you could use if the wire is broken, just brush the liquid across the wire to complete the connection. Otherwise I would remove the rear hatch cover (just like removing an interior door cover) and look in the upper corner. There are faston (wire) connectors going to the rear defrost, maybe they have corrosion and need cleaned or they have loosened and fallen off.

MountiansRcool

atleast u have a defrost

Unknown XJ

You can add it..... Just because its not there doesn't mean you can't do it. All the wires are there, You just have to finish it lol.
Courtesy of CCKEN:

Look for the Rear Window Defogger Relay
in the Junction Block. It's supposed to be
at the bottom just forward of the rows of
mini fuses. The fuse for the relay control
coil is in the JB, F12 (10A), the third
position up from the bottom on the
forward row of mini fuses. The relay
contactor power fuse is in the PDC, F11
(30A), it's the 3rd one up from the
bottom in the right row of maxi fuses (as
you look at the PDC from the grill).

Basically. you need the relay, fuses, rear glass with the defroster and the switch.