No brakes on trailer

cummins2014 wrote:


Could he just jack up one wheel, then pull the breakaway cable ,and see if locks up the tire, or do you have to establish it sliding the tires across the driveway , which doesn't sound like the best thing to do .

Yes.

As long as you don't mind jacking one wheel at a time, however, just because the one you picked works, doesn't necessarily mean the other three wheels are working.

That already HAS been mentioned in this thread.

Sliding the tires a couple of feet isn't going to hurt the tires, wheels, brakes or the trailer, but it does give you a real good indication of which brakes may or may not be in good working order all in one quick action..

Additionally, when hand turning a wheel and applying the breakaway, you only have a small amount of strength, far less than what your tow vehicle can apply.. It is possible to have the brakes strong enough to lock via hand but not be as strong as they should be, those brakes must be strong enough to stop and hold the entire trailers loaded weight.. Don't know about you, but myself, I don't think I would be able apply several thousand pounds of torque without resorting to a ten foot pole. Only pulling the trailer forwards or backwards will show just how good the brakes are working. In fact that IS one of the "tests" that my State Inspection mechanic does..

Do the divide and conquer troubleshooting correctly and you can easily bypass a lot of hard work (and guess work)in the process..

crazyro wrote:
I'd be amazingly relieved, but also frustrated and ashamed of the fact that I didn't think of it at first, and ashamed of all the time I've made all of you waste (but am SO thankful for all the knowledge shared). I'm still not out of the woods, but I'm hopeful...

But isn't this what it's all about coming here for help? Not a waste of anyone's time!
We learn from each other and none of us here are a genius.. (Well maybe a few self proclaimed ones.... ahem....):B
Certainly not a waste of time for us. :) We can all learn too. It's a good experience, and besides that, what else do we have to do here when cooped up because of some stupid virus floating around the world? Gotta preserve the sanity until we can all openly go camping again.
Glad you are making progress! Keep us posted!

Glad to hear the effort finally has some traction :B. (bad 4WD pun)

So, interesting developments tonight... Not only did I have to rescue my friend's trailer from a soft, muddy yard, his truck (2WD) got stuck as well. Do you need 4x4? Nope. Until you do... I've only had 4x4 and always will.
Hook up to his trailer, and to my dismay, all lights work, but truck won't recognize it. No brakes. At this point I had accepted my fate and was going to have the dealer look at and potentially replace brake controller. After getting both of them unstuck, I pulled the camper a couple of miles down the road. There, I kept messing with the connector, but nothing worked. Pins looked all good, we had die-electric grease on them, all seemed well. On a whim, I decided to move the 7 pin connector pins on my truck around. Pinched them towards the center, pinched center pins closer, etc. Plugged his camper back in, cranked up truck and the darn thing came to life! What the?
I didn't have time to go see if this fixed my camper braking issues, but if that was it, I'd be amazingly relieved, but also frustrated and ashamed of the fact that I didn't think of it at first, and ashamed of all the time I've made all of you waste (but am SO thankful for all the knowledge shared). I'm still not out of the woods, but I'm hopeful...

Gdetrailer wrote:

cummins2014 wrote:


Is it possible for the grounding on the brakes on this trailer the OP has to be faulty, letting the lights work, being on a different ground ???

No.

First, somewhere in the thread the OP already established that they did not have trailer hitched to vehicle and their lights do work properly.

Pretty much eliminates a ground wiring fault.

Not to mention IF there was a ground wiring fault, I can assure you the lights will not function properly. Typically, you will get some crazy lighting action do to the 12V finding alternate grounding paths.. May not see that as much with LED lighting but with incadescent bulbs you would get say one bright stop light and one dim stop light, things like that.

Rather than blaming wiring, truck, IBC and any other thing, it is much easier to break down the system in block or chunks..

We know that the trailer has a a breakaway system that can be activated without the truck electrical system connected..

So, lets use this to our advantage to help eliminate a bunch of variables..

Pull breakaway pin.

The breakaway switch now sends full on board battery voltage directly to the brake magnets.

Breakaway is supposed to LOCK AND HOLD the trailer brakes in a "on" position to stop and hold the trailer in the event that it breaks away from the tow vehicle.

If you attempt to pull forward or backwards with break away activated the wheels MUST not turn and the truck should be able to SLIDE the tires..

If wheels lock and slide then we KNOW for certain that the break away is working, we KNOW that the WIRING (positive AND GROUND) on the trailer is fine and we KNOW that all mechanical brake parts are setup correctly and functioning. In this case then we NEED to look at the TRUCK wiring and brake controller.

If wheels do not lock and slide when the breakaway is activated, then we KNOW there is a fault on the trailer and it is not the trucks issue.. In this case, the fault can be electrical or mechanical or even both.. But none the less we have eliminated part of the system..

Now if it is trailer, then we can further troubleshoot..

We KNOW that each magnet is rated to draw about 3A at 12V, we can use an ammeter in series with the on board battery to verify the current draw at 12V.. Note, there WILL be some variances due to battery state of charge, wiring size and magnet variations but it all should come close to 12A for all four magnets connected together..

should get reading close to 12A for 4 magnets.

about 9A for three

About 6A for two

About 3A for one..

If you get close to 12A for FOUR magnets then you have now eliminated trailer brake ELECTRICAL system..

Current much less than near 12A for FOUR magnets means you HAVE an electrical issue which could be broken/damaged wiring.

If electrical checks out then move on to the brake mechanical..

It is a thoughtful and logical way to troubleshoot and diagnose without randomly jumping to conclusions, blaming grounds, jacking it up or ripping things apart.

And yes, I went to school for Electronics theory including troubleshooting and repair many, many yrs ago, the same steps of breaking the problem down into smaller blocks using divide and conquer logic does work very well on other things besides TVs and Stereos..

Could he just jack up one wheel, then pull the breakaway cable ,and see if locks up the tire, or do you have to establish it sliding the tires across the driveway , which doesn't sound like the best thing to do .

cummins2014 wrote:


Is it possible for the grounding on the brakes on this trailer the OP has to be faulty, letting the lights work, being on a different ground ???

No.

First, somewhere in the thread the OP already established that they did not have trailer hitched to vehicle and their lights do work properly.

Pretty much eliminates a ground wiring fault.

Not to mention IF there was a ground wiring fault, I can assure you the lights will not function properly. Typically, you will get some crazy lighting action do to the 12V finding alternate grounding paths.. May not see that as much with LED lighting but with incadescent bulbs you would get say one bright stop light and one dim stop light, things like that.

Rather than blaming wiring, truck, IBC and any other thing, it is much easier to break down the system in block or chunks..

We know that the trailer has a a breakaway system that can be activated without the truck electrical system connected..

So, lets use this to our advantage to help eliminate a bunch of variables..

Pull breakaway pin.

The breakaway switch now sends full on board battery voltage directly to the brake magnets.

Breakaway is supposed to LOCK AND HOLD the trailer brakes in a "on" position to stop and hold the trailer in the event that it breaks away from the tow vehicle.

If you attempt to pull forward or backwards with break away activated the wheels MUST not turn and the truck should be able to SLIDE the tires..

If wheels lock and slide then we KNOW for certain that the break away is working, we KNOW that the WIRING (positive AND GROUND) on the trailer is fine and we KNOW that all mechanical brake parts are setup correctly and functioning. In this case then we NEED to look at the TRUCK wiring and brake controller.

If wheels do not lock and slide when the breakaway is activated, then we KNOW there is a fault on the trailer and it is not the trucks issue.. In this case, the fault can be electrical or mechanical or even both.. But none the less we have eliminated part of the system..

Now if it is trailer, then we can further troubleshoot..

We KNOW that each magnet is rated to draw about 3A at 12V, we can use an ammeter in series with the on board battery to verify the current draw at 12V.. Note, there WILL be some variances due to battery state of charge, wiring size and magnet variations but it all should come close to 12A for all four magnets connected together..

should get reading close to 12A for 4 magnets.

about 9A for three

About 6A for two

About 3A for one..

If you get close to 12A for FOUR magnets then you have now eliminated trailer brake ELECTRICAL system..

Current much less than near 12A for FOUR magnets means you HAVE an electrical issue which could be broken/damaged wiring.

If electrical checks out then move on to the brake mechanical..

It is a thoughtful and logical way to troubleshoot and diagnose without randomly jumping to conclusions, blaming grounds, jacking it up or ripping things apart.

And yes, I went to school for Electronics theory including troubleshooting and repair many, many yrs ago, the same steps of breaking the problem down into smaller blocks using divide and conquer logic does work very well on other things besides TVs and Stereos..

My lights worked just fine when I had the intermittent brake issue on my Boat trailer.

OP hook up your friends RV, I am betting the brakes work fine on his.

Gdetrailer wrote:

cummins2014 wrote:

Its been awhile since I have wired brakes on a trailer I've built. The one I did had tandem axles , it was an ATV trailer ,and I only bought one axle with brakes ,and the other without. I jumped one wire across to the other side ,and ran the blue wire to the plug, and I ran the other two coming off the brakes to ground on the frame each side. Plus when I ran the rest of the wires I also ran a ground wire to the frame coming off the plug. My question ,and I have to assume those brakes don't work if Their ground wires are broke or loose ,and not grounding . AlthoughI have wired a separate ground to the trailer from the plug ??

Granted, adding a ground wire at the axles can work, it was not recommended practice by Dexter Axle..

Dexter used to have a real good axle installation manual online that went into a lot of detail on the hows and whys to wire the brakes properly.. Looks like they removed that document from their library..

In a nutshell, by adding individual grounds in different places it is possible to get varying qualities in those different grounds, that is due to connection resistance, differences of resistance of the steel in the frame (and yes, steel has a much higher resistance than copper), electrical connections of the frame members..

In theory one can use the frame as a grounding point but in the real world what typically happens is slight differences in the electrical connections and those differences can be enough to affect how strong each magnet will be, some may be stronger than others which means the brakes are not in sync..

Trust me, you do not want brakes on one side of your trailer acting stronger than the other side.. It WILL pull you off the road or even worse pulling you into oncoming traffic.

By making a "home run" where ALL the brake magnets terminate to ground at the same spot, you now eliminate the off chance of having slight variations of magnet strength caused by a non common grounding point.

Additionally, on newer brake controllers, individual grounds CAN cause intermittent controller shut down.. They are that sensitive..

The fact that every trailer with factory electric brakes that I have owned came factory with all the brake magnets grounding done at the tongue should also speak volumes to the importance of this detail..

RV manufacturers are cheapskates, they won't spend a penny more than they need to.. If a single ground wire was not needed for proper operation, then they would not have spent the money on running one for the brakes to the tongue.. Would save them $10 per trailer and if they build 10,000 trailers that is $100,000 in savings they can pocket per yr..

I am going by memory, the ATV trailer is not here right now, or I would look to see what I did . Now that you mention ,I could of connected the two ground wires in the same place, ran them together, I had to on the blue wire up to the plug.

Being an ATV trailer that weighs around 1200 lbs, it brakes well. It requires my brake controller on my Ram truck to be turned way down ,or they lock up .

Is it possible for the grounding on the brakes on this trailer the OP has to be faulty, letting the lights work, being on a different ground ???

cummins2014 wrote:

Its been awhile since I have wired brakes on a trailer I've built. The one I did had tandem axles , it was an ATV trailer ,and I only bought one axle with brakes ,and the other without. I jumped one wire across to the other side ,and ran the blue wire to the plug, and I ran the other two coming off the brakes to ground on the frame each side. Plus when I ran the rest of the wires I also ran a ground wire to the frame coming off the plug. My question ,and I have to assume those brakes don't work if Their ground wires are broke or loose ,and not grounding . AlthoughI have wired a separate ground to the trailer from the plug ??

Granted, adding a ground wire at the axles can work, it was not recommended practice by Dexter Axle..

Dexter used to have a real good axle installation manual online that went into a lot of detail on the hows and whys to wire the brakes properly.. Looks like they removed that document from their library..

In a nutshell, by adding individual grounds in different places it is possible to get varying qualities in those different grounds, that is due to connection resistance, differences of resistance of the steel in the frame (and yes, steel has a much higher resistance than copper), electrical connections of the frame members..

In theory one can use the frame as a grounding point but in the real world what typically happens is slight differences in the electrical connections and those differences can be enough to affect how strong each magnet will be, some may be stronger than others which means the brakes are not in sync..

Trust me, you do not want brakes on one side of your trailer acting stronger than the other side.. It WILL pull you off the road or even worse pulling you into oncoming traffic.

By making a "home run" where ALL the brake magnets terminate to ground at the same spot, you now eliminate the off chance of having slight variations of magnet strength caused by a non common grounding point.

Additionally, on newer brake controllers, individual grounds CAN cause intermittent controller shut down.. They are that sensitive..

The fact that every trailer with factory electric brakes that I have owned came factory with all the brake magnets grounding done at the tongue should also speak volumes to the importance of this detail..

RV manufacturers are cheapskates, they won't spend a penny more than they need to.. If a single ground wire was not needed for proper operation, then they would not have spent the money on running one for the brakes to the tongue.. Would save them $10 per trailer and if they build 10,000 trailers that is $100,000 in savings they can pocket per yr..

One of the best electric trailer brake tester I've ever used is ....... a selaed beam headlight bulb.

Put two short wires on the bulbs spade lugs and first put it between the TV's brake lead and the ground pin. When first connected you should get a flicker then it goes out. Next have a helper manually apply brakes from inside the TV, it should fade to full brightness. If it does the TV & its wiring are fine.

Next put the bulb between the trailers brake connection and the TV's brake line with a jumper between ground pins. Repeat the above test. If the bulb fails to light, or lights but differently than the first test you can start digging further into it.