Wiring harness and electric brake questions

[TD Beej]

OK I have a 2005 Caravan and the standard trailer wiring harness is a 4 wire. I am thinking that is not really good enough, I would like to equip the trailer brakes so really a six or seven wire, unless I use mechanical actuators. Anyway looks will need to figure out my own harness, any suggestions?
Also, while I was thinking wiring/braking over I wondered why there aren't any ABS kits available, I found proportional brake controllers (and why aren't these located in the trailer instead of the TV?) and to get to ABS all you would need are a couple more censors and some additional programming. With the wheel sensors you could probably program an Ipod touch to do ABS and proportional braking.

Thanks,
Beej

[Shadow Catcher]

Being one who tends to over think things but also being a big fan of the KISS principle and parts left out don't go wrong.... The proportional control system is usually set so that it will not lock up the trailer brakes and in reality this is supplemental system not the primary breaking system.

[Yota Bill]

to wire it, use the existing 4 wires, minus the existing ground (upgrade that to a larger wire, AWG-12 or 10), then run a new wire for the brake (usually blue) and if you want, also an ignition switched positive wire for charging or other auxillary uses, and maybe even a back-up light wire, then just replace the connector.

As for the ABS and proportional braking on the trailer, ABS is just overly complicated for a trailer braking system, as Shadow Catcher pointed out, and if the proportional brake controller was mounted on the trailer, you would have to stop the vehicle, put it in park, and then get out and walk back to the trailer to make a minor adjustment. With it mounted within reach of the driver, the brakes can be adjusted for the terrain, load, weather conditions, etc. while driving.

[Dale M.]

I wondered why there aren't any ABS kits available, I found proportional brake controllers (and why aren't these located in the trailer instead of the TV?) and to get to ABS all you would need are a couple more censors and some additional programming. With the wheel sensors you could probably program an Ipod touch to do ABS and proportional braking.

That is exactly the problem more sensors and controllers... Now you have one brake system fighting the other....

Putting controller in TV actually extends TV brake control to trailer in stead of having independent system in trailer...

Don't make it more complicated than it really is....

Tow vehicle side...



http://www.easternmarine.com/em_store/t ... agram.html

Actual brake actuators at wheel are wired as below....



The Magnets are simply wired in parallel ( 2 or 4) depending on number of axles...

Inertia controller ( and most other controllers) usually depend on tow vehicle reaction to apply brakes as the trailer tends to push the tow vehicle, and they also depend on brake pedal timing (length of time you are actually on pedal) to determine how much current to apply to trailer brake magnets to actually apply stopping power to trailer brakes... The longer you are on brake pedal the more breaking energy applied to trailer (proportionally)...

Dale

[dh]

You can take a 4 flat trailer side connector and snip off the ground wire, put the three remaining wires into the 6 or 7 way, then you don't loose your 4 flat connector, just unplug it from the bigger connect if you need it.. Then all you have to do is run an upgraded ground wire and brake wire. Add a charge wire for breakaway battery if desired.

[dh]

One more reason the controller goes in the TV, lets say you have 2 or 3 trailers, do you want to buy 2 or 3 controllers? As stated above, you set the controller so that it will not lock the trailer brakes.

[TD Beej]

Thanks for the info on the 4/7 wire harness. I will get one of the 4 wire kits then get a 7 wire kits like this one http://www.etrailer.com/Brake-Controller/etrailer/ETBC7.html.

As for ABS braking simplicity etc. The technology is already made its way to commercial trucking and in an emergency situation any advantage you can gain could save lives so KISS is not the right way to look at it but rather a Cost Vs. Benefit is the right question.

And if KISS is invoked wouldn't it be a lot simpler to have the technology packed into the trailer so it is always there no matter how the TV is equipped, never have to fiddle with brake proportioning or time delays in braking action? Wouldn't mechanically actuated braking like boat trailers be simpler yet then then any TV controlled brake system so why aren't they used?

I hope the goal would be to get the most control smoothly, without sudden dynamic behavior changes for the least cost. There are sway sensors that apply braking on trailer available, ABS has been around for decades, and all (mechanical, proportional, timed) braking systems are all about decreasing stopping distances and improving vehicle control. It seems to me the best of these could be bundled up in a much more efficient and effective package. Who would need a proportional or timed trailer brake controller if the trailer simply calculates how much to brake to minimize pushing on the Tow Vehicle and does so with improved stability for both?

Think what could be accomplished by just having wheel rotation censors, an inertial sensor, and a force censor at the hitch. With just these you could accomplish ABS and DSC and all packaged in the trailer. The results would be much safer emergency stopping, braking on corners or in adverse road or weather conditions. All the bits to make this work are available but as far as I can tell no one has brought them together in
a kit.

From a design standpoint it doesn't make sense to package braking functions of the trailer with the trailer, it is certainly more elegant and easier to operate to provide that functionality in the trailer. It's time to do away with manually adjusting "automatic" brakes.

Sorry to go on so much and thank you for the input, it has helped crystallize what needs to be done.

Beej