Building a manual brake lockout switch

[thunder550]

One of the lakes near me has a long (10 mile or so) fairly steep downhill approach at highway speeds. This requires a lot of downshifting and engine braking to maintain a safe speed. Since surge brakes don't know the difference between slowing down with the brake pedal and slowing down with engine braking, this results in riding the trailer brakes the entire way down this hill. No good way around it. Every time we get to the ramp we can smell overheated brakes, and I've blown many inner seals this way, simply due to the amount of heat that's put into the hubs by the brakes.

On a previous vehicle I hardwired a manual brake lockout switch that would allow me to apply 12v to the trailer reverse wire, activating the brake lockout solenoid and preventing riding the brakes. I soldered a diode into the reverse wire upstream of my splice for the switch to prevent the switched power from back feeding into the vehicle and making the reverse lights come on.

Our new tow vehicle I really don't want to start cutting and splicing the wiring, so I'm planning on a removable version of the manual lockout switch using a pistol grip style momentary switch designed for hitch mounted feeders and a SPDT relay instead of the diode to prevent voltage from back feeding. The switch plugs into the cigarette lighter, and will be used to control whether the relay connects the lockout solenoid to the normal reverse wire from the vehicle or the 12v output from the switch.

Ordered parts last night, will document and take pics as I get started on this in case anyone else is interested.

Switch:
https://www.amazon.com/dp/B00FI6N6NE/re ... iAb5EDV38E

Waterproof relay with harness:
https://www.amazon.com/dp/B01N66W2XF/re ... iAb109ZJP4

SAE 2 pin harness (to make this plug-and-play):
https://www.amazon.com/dp/B0002Q80RW/re ... iAbYKT6ZPW

Heat shrink bullet connectors:
https://www.amazon.com/dp/B01FF1VHZK/re ... iAbB8F4H93

More to come...

[Tuscany]

IMO, Why not just convert over to electric over hydraulic brakes?
Expensive yes, but now you have total balance between trailer and tow vehicle. You will effortlessly brake under any situation.
Instantly activate, waterproof, and safe.

Your boat isn't small, and I'm surprised surge brakes are still allowed on a trailer over 6k GVWR.

[thunder550]

I'm planning on EOH eventually, along with adding brakes to the rear axle. Currently just have them on the front. Looking at probably $1200 or so to do that, plus a full weekend of work. Neither of those is in the cards at the moment, we (I) have spent more getting the boat up to snuff than we were planning on, and wifey has not-so-subtly hinted that she'd like for me to spend less time outside working on it too. I spent about $50 on the parts listed above, and I can build it inside the house.

[thunder550]

Planned wiring diagram

lockout wiring.jpg

[Big Block Power]

I don't brake going down hills I use the gas. Did that help I want to make it up the other side faster.

[thunder550]

Actual footage of BBP arriving at the lake...

[Big Block Power]

Nothing wrong with that. The bad part is I spilled my beer

[Tuscany]

Actual footage of BBP arriving at the lake...

[Tuscany]

I'm planning on EOH eventually, along with adding brakes to the rear axle. Currently just have them on the front. Looking at probably $1200 or so to do that, plus a full weekend of work. Neither of those is in the cards at the moment, we (I) have spent more getting the boat up to snuff than we were planning on, and wifey has not-so-subtly hinted that she'd like for me to spend less time outside working on it too. I spent about $50 on the parts listed above, and I can build it inside the house.

Haha, give it a few years. The question will be "don't you have something to do outside"?

[thunder550]

Haha, give it a few years. The question will be "don't you have something to do outside"?

Can't wait! Always have a list of about 50 things to get done around the house. As soon as our daughter is more self sufficient I think you are right. Problem is she's pretty good around me but super whiny and needy around mom. When mom's not home, she can hang with me while I'm working on stuff, run errands, be independent, and is generally content. As soon as mom comes home she needs some thing every 2 minutes, doesn't listen, gets whiny etc.

[NautiGirl]

Someone's a daddy's girl! That's ok... Not a bad thing for you or her! Dad's are the best! Teach her all the things to take of her own boat one day!

[thunder550]

Teach her all the things to take of her own boat one day!

Yes! If I have my way she'll be the quietly intimidating badass chick that all the boys are afraid of

[NautiGirl]

Teach her all the things to take of her own boat one day!

Yes! If I have my way she'll be the quietly intimidating badass chick that all the boys are afraid of

All the wrong boys will be afraid, but the right one will think she is awesome! Good luck Dad!!

[Bfun220]

When my daughter was little she was the strongest kid I knew. After putting up with her boy cousin till she couldn't take it anymore I watched her take him down and rub his face in the dirt . He thought that he was safe because he was 2 years older and a boy. I think boys being afraid help thin the herd.

[Big Block Power]

Teach her all the things to take of her own boat one day!

Yes! If I have my way she'll be the quietly intimidating badass chick that all the boys are afraid of

All the wrong boys will be afraid, but the right one will think she is awesome! Good luck Dad!!

Lmao

Sounds like mom gives in and gives her way too much and she is winning. Dad has it figured out. Our grand daughter is totally different around us then her parents. She knows who the boss is and what she can get away with. Still the best days of our lives
Nauti still runs around the hose making exhaust noises to this day. Brbrbrbrnroom