4 Pin to 7 Pin Adapter and power to the electric brakes

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Hfx_Cdn

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Sep 22, 2006
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Nova Scotia
    We're still in Florida, and it's been a long time since I've looked at a trailer wiring set up.  Our daughter is in the process of picking up a new to them PUP.  She tells me that it has a 7 pin wiring connector, and I know that their 2007 Jeep Liberty is wired with a 4 pin connector.  I see on line that there are adapter available, but it doesn't say if it would provide power to the electric brakes.  Do any of you know?
    Look out, that will make 3 out of 4 who will be RVrs, with the 4th a wanna be, but is into boating for the time being.

Ed
 
NO!
4 wire is for lights and turn signals only.
If the tent trailer has electric brakes they will need to install a 6 or 7 pin harness, and add a brake controller.
 
The 4/7 adapter lets you use a 4 pin trailer plug on a 7 pin tow vehicle outlet, but it doesn't work the other way. You can't get brake wire or 12v charging connections from the 4-pin cause it doesn't have any.

So if the PUP has brakes, she will need a 7 pin connector AND a brake controller as well. If the PUP doesn't have brakes (under 1500-2000 lbs GVWR may not), then the plug could be swapped out for a 4 pin.
 
    Thanks Gary, I'm going by what she's telling me.  It is a small 2005 Coachmen Viking PUP model 2170, I would have thought that if anything, it would have surge brakes, but won't know until I head north in a month.  But from what I see on the net, electric brakes were an option and the ad says it has them, and the specs shows a GVWR of 2,710 pounds.

Ed
 
To support Don and Gary, if the Jeep has only a 4 pin, you are missing the lines to control the brakes (blue wire) and keep the house battery charged (black wire) on the trailer.  I was in a similar situation with our old Suburban that had only the four pin.

I ended up buying one of these at my local auto parts store (Hopkins 47205):
http://www.hopkinstowingsolutions.com/products/vehicle-wiring-connectors/7-rv-blade/4-wire_flat_to_7_rv_blade_plastic_adapter.html

It converts the 4-pin to 7 and then gives you a place to run the two additional lines.  The nice thing is, the pin-out is already done for you preventing mis-wiring.  From there they will need to two fused feeds from the battery.  One runs to the brake controller to provide it power and the other to the rear of the Jeep to connect to the black wire on the connector.  Then, it is as simple as taping the brake switch for the brake controller and running a blue wire from the brake controller to the rear connector.

If that seems too confusing, here is a diagram for just the brake controller:
http://www.etrailer.com/faq-brakecontroller.aspx

Hopefully this helps more than confuses!

 
The key thing is that she will need to buy a brake controller for the tow vehicle and have it wired in.  I recommend the Tekonsha Prodigy "P" family of controllers. Local shops tend to install slightly cheaper brands/models or ones they have traditionally used, but the Prodigy series has superior technology vs many others (my opinion, of course).
 
+1 on the Prodigy.  I just installed one in my truck and it's a HUGE improvement over the Hopkins Brake Force controller I had before.  Not as cheap, but worth every penney.  Tekonsha has great phone support too!
 
Are you sure that the Jeep does not also have a 7 pin connector tucked up under the rear bumper.  I have a 2007 Jeep Commander and it definitely has both connectors tied up under the rear bumper.
 
    As I said above, we are still in St Petes, they are in Nova Scotia.  But, I am virtually certain that the Jeep did not have a tow package, so no wiring harness, I'm fairly sure it, and the hitch, was added by my son to let them use a utility trailer.

Ed
 
Hfx_Cdn said:
    Thanks Gary, I'm going by what she's telling me.  It is a small 2005 Coachmen Viking PUP model 2170, I would have thought that if anything, it would have surge brakes, but won't know until I head north in a month.  But from what I see on the net, electric brakes were an option and the ad says it has them, and the specs shows a GVWR of 2,710 pounds.

Ed

With a GVWR of only 2,710 lbs. it probably doesn't have brakes. Most states don't require brakes on trailers less than 3,000 lbs.
 
A Liberty is not a very large SUV.  If the trailer has electric brakes, all it would take to make it safer to pull with the Liberty is a brake controller and a blue wire of suffecient guage run to the connector.  I would hook up the trailer brakes for added safety for yout Daughter.  If you do not have a controller, I have an extra one that I will give you for your peace of mind regarding your daughter.  It is a Prodigy.  PM me.
 
DavisK is right that most states have a 3000 lb cut-off for trailer brakes, but several do not and have either a lower limit (as low as 1000 lbs empty) or they specify a minimum stopping distance instead of a weight. Some of the Canadian provinces have lower limits as well. For that reason, many trailer manufacturers include brakes as standard on smaller trailers, or dealers order them with optional brakes so that they will be legal wherever they travel.
 
Check if the trailer has brakes.  Someone might have put the 7 pin connected on the trailer because their tow vehicle had one.    I changed a 17/8 hitch on my ulitel trailer so I would end haft to keep changing my ball on my truck  now all my trailers are 2in 
 
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