another trailer wiring question

[jamesx2]

My tow vehicle is a 02 Mercury Mountaineer with the factory tow package.
It came stock with a class 2 hitch and a 4 pin connector.
I went to Uhaul today and ordered a class 3 hitch that mounts to the class 2 hitch. It kind of sits under and in the original hitch.

My battle today was with the wireing.
I removed the passenger tail light cover and found a 7 wire plug going into the 4 wire flat plug. Uhaul sold me a adapter that plugs the 4 pins together and on the other end is a 7 pin to the trailer.
They also sold me a brake controller but not sure if i need it as I cant pull the trailer yet
All lights work and using the multi meter I am getting power to the brakes.Do i need the brake controller or does the Merc have it built in?? How does it know how much brake to apply?

Even the Uhaul guy was confused. First I ended up buying a harness that plugs into a plug under the dash for the factory brake controller but theres not one there

Whats going to happen when I step on the brakes??

 

[jrford]

My tow vehicle is a 02 Mercury Mountaineer with the factory tow package.
It came stock with a class 2 hitch and a 4 pin connector.

That makes it Class II they all sorta come with a tow package, but your limit is still 3200lbs.

All lights work and using the multi meter I am getting power to the brakes.Do i need the brake controller or does the Merc have it built in?? How does it know how much brake to apply?

Your missing the Brake Controller still need to buy one.


Now you know you can replace the Class II with a factory Class III from the junkyard, its a bolt on, and you should also get the harness that plugs into that 7pin under the tail light.

 

[rrgone]

My tow vehicle is a 02 Mercury Mountaineer with the factory tow package.
It came stock with a class 2 hitch and a 4 pin connector.
I went to Uhaul today and ordered a class 3 hitch that mounts to the class 2 hitch. It kind of sits under and in the original hitch.

My battle today was with the wireing.
I removed the passenger tail light cover and found a 7 wire plug going into the 4 wire flat plug. Uhaul sold me a adapter that plugs the 4 pins together and on the other end is a 7 pin to the trailer.
They also sold me a brake controller but not sure if i need it as I cant pull the trailer yet
All lights work and using the multi meter I am getting power to the brakes.Do i need the brake controller or does the Merc have it built in?? How does it know how much brake to apply?

Even the Uhaul guy was confused. First I ended up buying a harness that plugs into a plug under the dash for the factory brake controller but theres not one there

Whats going to happen when I step on the brakes??

I think all the Explorers in this generation have the harness and connector to plug a brake controller into located under the dash on the passenger side. Not sure about the Mounties though. Drop the glove box down and look left and up for a connector taped to a wiring bundle. Mine has a gray connector there for the controller adaptor.

A good resource for questions about towing is to look at the towing guide for your year/model here:
https://www.fleet.ford.com/showroom/rv_trailer_towing/default.asp

 

[jamesx2]

I think all the Explorers in this generation have the harness and connector to plug a brake controller into located under the dash on the passenger side. Not sure about the Mounties though. Drop the glove box down and look left and up for a connector taped to a wiring bundle. Mine has a gray connector there for the controller adaptor.

A good resource for questions about towing is to look at the towing guide for your year/model here:
https://www.fleet.ford.com/showroom/rv_trailer_towing/default.asp

You are a life saver!!!
After days of looking for the plug you sent me right to it.
I hooked the controller up. I thought all was ok until the brakes still didnt work. No power to the plug.
I removed the tail light again an looked at the wires. Blue is in the loom at the plug but not on the end where it plugs into the stock 4 pin.
Another thing that Merc deceided to hide. THe end of the blue wire was folded back and taped up .
I hooked the blue wire to the blue wire on the trailer plug and it works perfect

Thanks again.
Now comes the fun part of fine tuning the brakes

 

[rrgone]

Good deal. Thanks for the feedback.

 

[jamesx2]

Now that I have a class 3 that hangs off the class 2 hitch and is bolted into the frame rails. Is it a clas 3 or class 4?
It seems that it would be twice as strong as the class 2plus some
Pics soon