Well that title says it all. I found trailer plug on back that was caped but it's only 5 wires and I believe I need 7 for brake controller and lights. Is this pre wired or not?

 

Depends on the options your van came with. You can get a build sheet from here. (go to equipment listing.)

Yes, you need 7 wire harness for brake controller.

 

One wire in a 7-way is optional as it can be used for different things such as back-up lights or 12-volt battery power. The ground may also be taken from the back of the vehicle so it wouldn't need a wire. I would get out a test light and start poking around.

 

Just hard wired it. Still cant believe a 3500 van does not come with hitch wiring.
Thanks all.

 

I have the 3500 cargo van with tow package, owned it since new.I do have the tow package, so wiring was plug and play for 4/5 wire flat plug which I bought the harness @ local parts house to tow my enclosed trailer with no t-brakes. It supplies power for lights and turn signals only.

So far as I know and can recall, if adding a brake controller you'll need to provide wiring for power for trailer brake/controller power, and back to the 7 way plug, which should be included with whichever brake controller you purchase's instructions