Question about having hitch & wiring put on...for pulling popup

[DeeBee]

I hope someone can answer my questions about the wiring of a new hitch. My daugher has a 2017 Highlander. Tomorrow they are putting a hitch on her car and they told us the wiring will be a 4 prong plug. They said it is kept in the trunk and pulled out (with the door closed on it) when she needs it. She is actually having it put on because she is hoping to buy a popup in the near future...which I believe needs a 7 prong plug...am I correct? So when she buys the popup, does she have to have the wiring redone? How do they put the 7 prong plug on? Is it done with an adaptor? Will the 7 prong plug be pulled through and enclosed in a bracket with a cover to protect it? If anyone has any info on this, I would appreciate any insight about this. Thanks so much.

[RogerR]

a 4 way provides stop, turn and running lights. A 7 way has the ability for backup lights, rv battery charging circuit and most importantly the wiring for trailer electric brakes.

If you don't have brakes or backup lights and don't need to put any charge into the Rv battery you can get an adapter that plugs into the 4 way.

Or you can have it pre-wired to a 7 pin. then you can get an adapter if you ever want to pull a 4 pin only. Most popups use 7 pins even though they don't have electric brakes.

Why make two service charges?

[JFlightRisk]

If they insist on installing only the 4-prong connector, here's a kit from eTrailer that'll get you a 7-prong trailer connector. If there's no brake controller, you'll need one of those, also.

https://www.etrailer.com/p-ETBC7.html

The eTrailer customer service is great, so if you have questions, they'll be glad to help.

[NewBlackDak]

Every pop up I’ve towed had surge brakes.

[Jim Davis]

I have a Highlander and had the hitch and wiring done by a RV dealer. They did a proper seven pin and break controller. As I understand it if a Toyota dealer does the job he will normally do a four pin as that is what the vehicle is set up for in a down and dirty installation.

[DeeBee]

Thank you for the replies. So here is how it turned out. We are getting a Draw Tite hitch that is good for weight bearing towing or can accept a weight distributing hitch (in case we would decide to go with small trailer later instead of popup). They will put the 4 prong plug on for now, and later when the trailer is bought they will put on the brake controller and 7 prong plug. The brake controller costs quite a bit so we will break the purchase up into 2 separate purchases (hitch now, brake controller later). They told me (and hopefully it is true), it will make no difference now...they have run extra wires later for the 7 prong plug. Right now hitches are in such demand, they are hard to find the one you want. We were lucky to find one and get an appointment to have it installed within the next week. I think the pandemic has caused a hitch shortage!
PS. I realize we probably won't need a weight distributing hitch but a rv dealer told me they are recommending weight distributing hitches even for small trailers now. I don't know if that is to protect them or it is really safer, but at least with this hitch the option is always there no matter what we buy.
Thanks again.