replacing rear lift gate (fully assembly)

Hi all, I have an 07 and am replacing the rear lift gate with that of an 03, due to rust and power window issues etc.
The 03 that I am attempting to put on has a spoiler on that back while my 07 does not.
I noticed that the wiring harness is not compatible as my 07 wiring splits into 2 with the second wire plugging into a black box under the headliner, I can unplug this but I am sure that box does something. The 03 does not have this split in the wiring.
The 03 (with the spoiler) ,meanwhile has it's own split in the wiring to power the light in the spoiler.
Are these two just not compatible? or is there something that I can do to get the new one on an working.
Thanks for any and all help.

 

then swap the wire harness out, I would think the power motors are the same so it should just plug right in.

those extra wires are needed for something as you guessed and it would be my guess its related to the automatic rear window remote function or the automatic soft close feature

I don't think the early 03-04 4th gens had those features

check this link to confirm and see what changes were made http://www.top4runners.com/runhist/runhist42003.html

 

Thanks I did not think about that being for the remote power window. The liftgate that I am putting on does not have the extra wires as it is older and most likely does not have the remote feature. I will just unplug it and not re connect it, I can live without the remote feature as I very rarely use it.

 

my point is, the stuff for it to function is right there in your old gate so why throw it away? just unbolt it and bolt it into the replacement gate along with the original gate wiring harness. these things all use standard mounting points so im sure it wont take you more then 5 minutes to do.

at least remove that stuff from the old gate and store it in a safe place in case you find out later you need it or if you ever want to sell it you will have to hook it up then.