7 PIN INSTALLED WITH 12 GAUGE AND 20AMP FUSE

Busdrivera321

Okay I have the T@B 320s and am towing with our 2020 Outback XT. All good so far right? Well I had a shop install the 7 pin and I purchased the Curt Echo wireless brake controller. Now were starting to get to my problem, Hot wire battery fuse is burning through. It is rated for 20 amps and the brake controller requires 30 amps. The 7 pin was installed using 12 gauge and from what I read I'll need 10 gauge to run a 30 amp fuse. Could I just use less breaking force through the controller i.e. set the power to 30 vs 50. It came set at 50 for the force. I don't want to have to rewire. Ugh, small worl problems I know.

MuttonChops

@Busdrivera321 ;  IMHO you should return to the 7-pin install shop or return the Curt Echo.

Talk with your 7-pin install shop on having them upgrade to 10-gauge wire and a 30-Amp fuse. It is possible that during hard braking, as Curt warns, and you are already seeing the 20A fuse will blow.

Now some factory installed 7-pin systems only have 20-Amp rating, Honda Ridgeline for example, so these vehicles would not be Curt Echo compatible without upgrading the wiring.

As for the Curt Echo.  An interesting product . . . but . . . maybe it's not the ideal solution. A more standard wireless controller with an in TV control display might be better for you overall.

The Curt Echo also has one design feature / issue that is concerning. Curt's  "How it Works" video says that when the TV hazard lights are on the trailer brakes will pulse on/off with the lights . . . so you cannot safety turn-on you hazard lights (flashers) while moving.

This design feature is noted in the Video only . . . I've not been able to find it in the installation instructions and can't local a product owners manual.

For myself not being able to use the Hazards while moving is a show stopper.
+++ I use them when backing up
+++ I use them on the highway to warn following vehicles of nearly stopped traffic
         until there are a few 'also going slow' cars behind me.

Busdrivera321

Excellent! Are there ones that you don't have to mount to a surface?

ChanW

I'm baffled why a brake controller would require 10ga wire and a 30A fuse...

Is that right? What is it I'm missing?

Denny16

The hot 20amp wire on the 7-pin is used to activate the brakes in the trailer and charge the trailer battery.  Perhaps between the two, the 20-amp fuse is blowing, I do not think,this has anything to do with the brake controller, which draws less than 1 amp itself, and just passes the connection to the brakes, hence the 30-amp requirement to do both.  On a hard brake, at 20-amp, it is getting maxed out.
cheers

MuttonChops

ChanW said:

I'm baffled why a brake controller would require 10ga wire and a 30A fuse...

This seems to be specific to the Curt Echo controller design.

Installation instructions state:

ChanW

Ah, thanks. That makes more sense.

MuttonChops

@Busdrivera321 ; some updates to my earlier post

MuttonChops said:
Talk with your 7-pin install shop on having them upgrade to 10-gauge wire and a 30-Amp fuse. It is possible that during hard braking, as Curt warns, and you are already seeing the 20A fuse will blow.

Now some factory installed 7-pin systems only have 20-Amp rating, Honda Ridgeline for example, so these vehicles would not be Curt Echo compatible without upgrading the wiring.

Found a Prodigy RF Installation/Use Guide. Prodigy is 20-Amp wiring compatible.

Text from installation instructions:

And . . .

MuttonChops said:

. . . Curt's  "How it Works" video says that when the TV hazard lights are on the trailer brakes will pulse on/off with the lights . . . so you cannot safety turn-on you hazard lights (flashers) while moving.

Prodigy RF also uses TV brake light sensing and will pulse the brakes if Hazards are turned on.
There is a thread on this forum discussing:

https://tab-rv.vanillacommunity.com/discussion/8716/tekonsha-prodigy-rf-wireless-trailer-brake-controller-issue-noted-when-towin

ckjs

The Autowbrake controller i just added to our 320 *also* pulses the brakes when the hazards are on. I was so disappointed. Are there any brake controllers that behave correctly without needed to be wired to the brake pedal switch?

MuttonChops

ckjs said:

The Autowbrake controller i just added to our 320 *also* pulses the brakes when the hazards are on. I was so disappointed. Are there any brake controllers that behave correctly without needed to be wired to the brake pedal switch?

Based on reading, not direct knowledge, suspect all the Wireless controllers will have trailer brakes pulsing with hazards. So short answer is No.

They all seem to use the TV Brake Lights On to activate then use their accelerometer to decide how hard (proportional) to apply the trailer brakes.

Curt Echo does have a software Hazard Override settings option. Setting Hazard Override On will allow the hazards to flash without causing braking. However, to have braking while the hazards are on
Driver Must Press the Manual Brake Button
. . . not a great solution since when hazards are on generally driver is already very busy . . .   Also description of this software feature found on eTrailer, quoting Curt Support, is not 100% clear if Driver Manual Braking is needed all the time or just when hazards are active.

When purchasing my T@B had planned on doing a wired controller based on price differences. With this new knowledge on wireless would have been very disappointed with how they handle hazards.  In the end purchased a TV with factory installed controller at a very reasonable option price, win win for me.

Denny16

Yes, a factory type brake controller designed for the specific TV is the best solution.
that said, it is illegal to drive with hazard lights on while moving, this is the rule in Calif., but a lot of folks do it.  Flashing lights around here are for emergency vehicles only.
cheers

MuttonChops

Denny16 said:

. . .  it is illegal to drive with hazard lights on while moving, this is the rule in Calif.,

Truckers climbing hills well below speed limit use hazards all the time, they are a hazard.
Last Trucker in a long line of nearly stopped highway speed zone traffic also use hazards to warn approaching vehicles, another hazard.

Just saying, there is a time and place for when hazards while moving makes sense.

Denny16

Good point.  But these trucks are going very slow, under 20 mph, so is a valid use, as is stopped in a traffic lane or shoulder.  I use mine when almost stopped on 2-lane Hwy 1 when some one is stopped trying to turn left.  But having a brake controller pulse your brakes is an issue, if you are trying to go slow, like up a steep grade.  
Cheers

Busdrivera321

Alright I found the possible cause! Part of the 12 gage wire was  crimped and grounded to the TV's frame. Also for 2020 Outback owners with factory hitch, I relocated the 4 pin to under the bumper with zip ties and bolted the 7 pin in it's place. Much cleaner look than having it attached to the bumper fascia.

Busdrivera321

Quick follow up, my brakes don't pulse with hazards on.....very strange. Now I want to go camping so bad. After reading MuttonChops post I looked at my Echo app and hazard override was selected

MuttonChops

Busdrivera321 said:

. . .  my [Curt Echo] brakes don't pulse with hazards on

. . .  looked at my Echo app and hazard override was selected

Good to know, real-world confirmation.
Now have you confirmed the brakes work normal with the Hazards Off while override is selected ?

If bakes are normal would guess Echo has some type of timer to detect and ignore toggling brake lights - - - so watch how you pump the brakes, don't want to copy hazard on/off timing

Busdrivera321

Real quick update on testing the Curt Echo brake controller. I've set the power to the brakes at 35% and sensitivity to 3 in order to send less amperage through my system. I am sticking with a 20 amp fuse at the TV battery in order to not burn up the 12 gauge wiring. It has worked so far. Braking is good, but I did look at the Echo smart on time and it was showing brake application. I didn't notice any appreciable deceleration. It only came on for a moment. I have received excellent help from e-trailer, the hitching post and NuCamp. All said I could run  a 30 amp fuse but I feel more comfortable with the 20.

Busdrivera321

MuttonChops, not really. I will test as soon as I can and report findings. Thanks for all your help.

WilliamA

For calculating electric brake draw, one needs to start at the magnets or "pucks". There is one magnet inside each wheel hub, so a single axle trailer has two.  For standard 7" or 10" brakes (T@B, T@G etc) the MAX amperage draw per magnet is in the neighborhood of 3-3.5 amps.  So the total draw during hard braking is around 7 amps max. You need to factor in around 3-5% loss for wire length. Just figure 1/2 an amp for that. This brings the total amperage load to less than 8 amps. For normal braking, not neck-jerking stops, you'll probably have your controller set to 50% or less.
If you are roasting your wiring and blowing a 30 amp fuse, you've got bigger problems. Here's a wire sizing chart:
http://fettingpower.com/home/helpful-references/wire-sizing-chart/

You can figure that a circuit should be sized at the capacity of the fuse, or the maximum amperage potential of the fuse. For a twenty amp fuse more than 10 feet long, you will need a 10 gauge wire.  Not difficult to calculate.

Let's assume that ALL electrical connections are good. (This is not the case with my T@G. I ended up replacing several splices within the wiring due to failures.) Remember that in a 7 way circuit, there are more than brake amperage requirements. If you add up the individual potential amperage in ALL of the circuits, you'll find it's a surprisingly high number.  All of that current potential feeds to the trailer on separate circuits, BUT! It all returns to the tow vehicle on ONE wire! The ground wire in the 7 way connector must be capable of handling the combined amperage of all 7 circuit potentials.  Thankfully, this rarely happens and when it does, it's usually for no more than a few seconds at a time.  You've got a 12 gauge (too small) wire going to the brakes, a 10 gauge charging wire, 16 gauge wire for various light circuits.....and one...single 14 gauge wire for the trailer ground. That is going to be one hot, busy wire. Do yourselves a favor:
First order of business in trailer wiring should be to make sure the ground wire coming from the trailer, through the 7 way receptacle, then back to the tv battery (not duct-taped to the exhaust tip for a ground) is 10 gauge, has proper butt connectors,( crimp-on connectors are fine so long as they are either heat-shrinked or are the heat-shrink type. These can be had at any auto parts store. They have a heat sealer within the connector so when you heat shrink them, the sealer melts and completely coats the inside of the crimp. Expect to pay $6 bucks or more for 5 or 6 connectors. If you are bound and determined that you don't need to run the trailer ground back to the tv battery, then at least use a nickel plated ring connector that won't rust, then seal it with some sort of coating to keep the water out.
99% of ALL light, brake, charging circuit problems on trailers can be eliminated by paying attention to the ground wire that goes from the plug to the chassis/battery on the vehicle side. If you go out and look at the ground wire on your vehicle-side trailer wiring, you'll see that it's no larger than the turn signal wire.  I've seen factory and aftermarket wiring harness plugs that are as small as 16 gauge.  NuCamp runs 10 gauge ground wire through the trailer connector to the plug. Do the same on the other side of it and you'll eliminate 90% of your problems. You might (will) also find that your tow vehicle can now charge your trailer battery in 1/3 of the time.

WilliamA 

Denny16

Grand advice, folks do not realize the ground connection carries more than just the light circuit load.  A lot of trailers use the frame as a ground, with a #14 wire to the 4/7-pin connector, and the wire to frame connection is not very good, and fails.
cheers