hartop rear defrost question

[jaketime81]

I bought a oem hardtop, wireing harness, and defrost switches for my tj and the rear defrost is has never worked. the rear wiper works, and the swich lights up, but it does not turn on when I press it. The fuse is good and I put a relay in the stock slot under the hood. What wires can I check or where should I start to figure it out?

 

[Snitty]

i would first test the wires at the rear... when the switch lights up... it is simly telling you that the relay is powered... it won't tell you much about the rear being powered