I never put a hitch on my 2019 Jeep GC because they wanted to charge me $150 to program the computer to make the lights work. They would only use and install the factory harness at a cost of $200 part only. The only other option was wire it into the tail lights which would void the computer warranty and it costs $400 just for the part. This could have been all BS, I just decided not to tow with it. The hitch was easy as it had four bolts and the frame already had the holes. Hitch at U-Haul was $225.

 

Seems high, The OEM hitch bolts on in about 15 minutes,with no bumper removal.
The wiring goes into the the rear lights through the back of them..you take off both lights and wire it that way.... another 30 minutes tops.

 

If you are not under warranty that is the best way to do it. If not it will void the computer warranty that runs the lights. I seem to remember the dealer told me the vehicle has 7 computers. I think that could all be dealer smoke and mirrors.

 

JSUKnoww
I purchased 60.00 worth of aftermarket bumper hitch and receiver parts with wiring, for a 2018 2-door Wrangler JK.
Took product and jeep to my local guy and charged me 300.00 labor due to fact he had to drop rear bumper to gain access to all bolts.
I was floored!!!

What floored you? That he charged you $300? Here in California, that's about an hour and a half of labor, not sure where you are, so might be less. Or, that he had to drop the rear bumper? Maybe because the hitch was aftermarket, rather than OEM?

 

You can install that OEM part but Jeep has to activate the computer to make it work, so I'm told. Yes mine is a WK 2019. The way U-Haul does it is tap into the lamp socket for power to use the harness they sell. That is what will cause a warranty issue if something happens, I'm told my WK has seven computers in it.

 

The JK is different than the WK ..Neither OEM nor aftermarket wiring requires activation.
As far as your WK having 7 computers, its closer to 30 depending on trim level. A Wl has about 45.

 

I'm not surprised the dealer would lie to me about the activation. Now I wonder just how many computers mine has as it is a 2019 Grand Cherokee Limited with all the options V6 2WD

 

We installed the hitch and wiring harness on my son’s JK in a couple hrs very easily with no problems. The install of the factory hitch & harness on a WK-2 (I think that’s what the OP is talking about) is much more involved. For the factory hitch install the whole rear fascia has to come off and the rear bumper crash bar removed; the factory hitch takes the place of that. Then for the factory 7 way harness it takes about 6 hrs of labor to install, my dealer showed me the actual instructions, 28 pages and a lot of dis-assembly. I decided to pass on 2 nice late model vehicles because of this. If all you need is a hitch and a 4 flat harness yes you can go aftermarket for both but I’m not sure if adding the aftermarket harness that connects to the rear lights will cause trouble & violate the warrantee.
My 2007 WK-1 came with the factory hitch and harness (7 way) and on my old 1998 I installed both myself but those were much simpler vehicles.
Keep in mind choice of the harness determines what trailer you can tow. A factory 7 way allows you to tow any trailer within the tow rating, with a 4 flat the only trailers you can tow are those with either no brakes or surge drum brakes like on boat trailers. If the boat trailer had disc surge brakes you need that 7 way & a 7 to 5 way adapter.
If you are towing an RV or landscape or cargo trailer nearly all of which have electric drum brakes you need a 7 way for sure and an electric brake controller in the tow vehicle.

 

We installed the hitch and wiring harness on my son’s JK in a couple hrs very easily with no problems. The install of the factory hitch & harness on a WK-2 (I think that’s what the OP is talking about) is much more involved.

The OP is actually talking about a JK, which as you know is a very easy install for both the hitch and wiring. ..
I'm not sure how we ended up on the WK, but this one went off the rails somewhere.