Trailer Brake Adjustment, etc

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Tue, 06/28/2016 - 16:49
#1
Going Light
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Last seen: 5 months 2 weeks ago
Joined: 05/30/2016 - 20:11
Trailer Brake Adjustment, etc

Hi everybody,

I just got my trailer brake controller installed. (Subaru 2013 Outback, towing capacity 2750 lb; 13' standard Scamp.) My car is rated to do fine with the Scamp without the controller, but everything I read from all you folks says get the controller, and use it. So I did, partly because sometime in the next couple years I'm going to Scamp my way to Alaska; and partly because I love the idea of re-charging the marine battery plus operating the refrigerator while on the road.

I'm reading closely through the Tekonsha P3 instructions, and there are a couple things I have questions about. 

First of all, on page 9 (Troubleshooting section, god send I never have to look at this again), there are displays illustrated for various conditions. One of these is "Stoplight. Displays voltage supplied from stoplight switch with brake pedal depressed (red wire)." Eh what??? What on earth is "Stoplight"?

And then, what exactly should all these voltages be (Battery Voltage; Stoplight; Output Voltage; Output Current), when everything is operating correctly?

Second, page 6, in the note 5 under the heading Adjusting the Power to the Trailer Brakes, it is stated, "When the power is set correctly you should feel unified braking between the trailer and tow vehicle." To tell the truth, my Outback does a damn good job of braking the whole outfit. I always slow down and apply brakes early. Only once, when I decided rather late to brake for a yellow light, did I have to press harder on my vehicle's brakes than I would normally have expected, when not towing. So am I really going to be able to detect this? (Maybe I need to have a mechanically sensitive person ride along. Or actually drive it. Hm.)

Third, here's a somewhat scary proposition. Page 11, Trailer Brake Adjustment. "Brakes should be adjusted after the first 200 miles of operation, when the brake shoes and drums have 'seated,' and at 3000 mile intervals, or as use and performance requires." Then there are instructions on how to do it. Do these instructions make sense to all of you who have done it?  . . . I'm a little "uff da" about this, because I don't think I'm necessarily going to put 200 miles on the Scamp before I head for a summer gathering that's about 450 miles away. No way I'm getting it up on jack stands halfway down there. How important is it to do this? Should I just go drive around for a few hours, braking here and there, and make sure I get the trailer brakes adjusted before I go off on this trip?

Thanks for your expertise and advice on all this. I treasure my little Scamp and want to do the right thing by her. 

Joan

 

 

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Tue, 08/16/2016 - 08:54
Gordon2
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Last seen: 1 year 1 month ago
Joined: 04/26/2015 - 09:01
RE: Trailer Brake Adjustment, etc
  1. Brake controller has nothing to do with recharging the trailer’s battery or running the fridge.  I don’t know a thing about your Outback but unless they prewire it for a charging line (unlikely), the charging line will be a separate add-on and unless you installed it, probably does not exist.
  2. Stop light is your brake lights. When (and only when) your foot is depressing brake pedal you should see about 12-14 volts. If you don’t, then your connection to the brake pedal has failed and your trailer’s brakes will not activate.
  3. “Input voltage” (power going into the controller) should be about 12-14 volts (on the high end when the Outback is running). The output voltage will vary from zero, to the same as input voltage, depending on the setting of the controller..as you move the manual lever the voltage should increase up to the max setting on the controller. The voltage will increase even with no trailer connected but the amperage will only if the trailer's brakes are connected.  Max amps should be under seven for the Scamp 13 (7 inch brakes) but maybe well under 7 amps in practice. My Scamp 16 draws only a few amps when braking MOST of the time. The  faster you decelerate, the more power is sent to the brakes.
  4. When the brakes and controller are perfectly adjusted, you should NOT feel the trailer “pushing” or "dragging" the Outback when you brake.  Ideally, braking should feel about the same as it does without the trailer.
  5. I would not worry too much about the adjustment at 200 miles, esp. since you think the Outback is beefy enough to stop the trailer even without trailer brakes. Just do it as soon as you reasonably can, or sooner if braking ability suddenly changes in an appreciable way. You could probably just increase the gain (adjustment) on the brake controller a little to compensate until you can do a proper adjustment.
  6. Good idea to drive around locally and break in the brakes a little, if for no other reason than to make sure they are working well.
  7. I think it’s good that you are using trailer brakes but if there is doubt about how well they are working, or how the brakes and controller are adjusted, then seek expert in-person help.  The brakes will definitely help you stop in shorter distance and that can mean the difference between a collision and a non-event.  Plus, lack of trailer brakes would no doubt mean more frequent servicing of the Outback’s brakes and that can add up in expenses.

You probably have all this figured out by now but maybe this info will help someone.

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