I have a question for the Expy/Navi owners that use their trucks for trailering:

I'm borrowing a friends tandem axle landscape trailer (7000# GVWR) with electric brakes on the rear axle.

I hooked it to my '02 Navigator ((w/ heavy duty tow package, (round 7-pin connector) ) and at ~5 mph hit the brakes and the rear axle of the trailer seems to slide the rear wheels in gravel !

So, my question is, are the electric brakes on the trailer functional even though I don't have a brake controller plugged into the brake controller connector under the dash?

I was under the impression that I need a brake controller for the electric brakes to work. If I don't need a controller, is there an advantage to using a brake controller?

Thanks in advance for any information you can share .....

 

I'm not sure about the brakes working without the controller, but I can tell you the benefit of the controller is the ability to balance the braking power of the trailer in it's empty and loaded states to prevent early or late braking. You don't want the trailer locking up the brakes, and you don't want it going past you while you are slowing down and it isn't slowing enough. It is pretty important with a heavy load.

 

Typically there are only brakes on one of the trailer's axles and it certainly sounds like the trailer plug is causing some type of activation.
Try it without the trailer plug connected, does it still lock up the same axle?

When I built my boat trailer I put the brakes on the front axle, where the weight was and the stopping inertia pushes the load being carried.

As mentioned, I would not tow a trailer that big without a Controller that is adjusted properly.

 

It sounds like the owner has wired the brakes into the stop-light function of the wiring harness, which is illegal. The reason for the brake controller, is to apply a charge to the brake line in proportion to the amount of inertia being placed on the controller. It also allows for proper adjusting of the brakes, so they do not lock up at full signal, except in the most extreme of conditions. Also it is typical for a trailer over 3000lbs to have brakes on all axles, not just one. Some states require brakes on one axle, and some require brakes to be on both. Most trailer manufactures supply trailers with brakes on all axles, as nobody can really plan on where a trailer is going to end up. I actually work in the trailer manufacturing industry, we put brakes on all axles on any road going trailer over 2000lbs, regardless of axle count. Electric braking trailers must be equipped with a breakaway switch as well, so it's possible the device is malfunctioning and supplying voltage to the brake line.

 

You need a controller. If the breakaway is pulled the braking action would be constant the wheels would be locked.

Given the amount of weight you are towing, I believe you are towing illegally in all states but one.

Steve

 

Where is the plug for the controller located? I have a 98 Expy with the heavy tow package.

 

Under the dash - near the OBD-II connector.