2021 30kqbss - brake controller “Overload”

[WildwoodWarners]

Just picked up our used 2021 30KQBSS. We trailered our 2018 Springdale and traded up for this one.

On the way back with the new trailer the brake controller started saying Overload. It came and went on the way home then finally every time I hit the brakes it warned me.

I have read that newer trailers that have very little miles on them may need to adjust the brakes on the trailer. If that’s the case is it still possible that I would get an overload condition on the controller and not just soft breaks ?

[SeaDog]

welcome to the forum its a great place to get your questions answered. What is your tow vehicle? that might help with the answer to your question. I think I would start by checking all the connections to the breaks. Maybe you have a wire chaffed or bad connection causing the overload. JMHO

[WildwoodWarners]

Hey SeaDog,

I’ve got a 2022 2500HD. I have always used a external brake controller, a Prodigy 3. I haven't had any issues with this setup all last year nor with the old trailer on the trip out to the dealership.

I did inspect the truck 7-pin and the trailer side and didn’t see anything wrong.

I’ll dig into the trailer side a bit more, junction box as well as the connections at the brakes.

Really didn’t think I’d have any issues since this trailer isn’t very old and was barely driven.

[MillMitch]

Welcome to the forum from MN.

[WildwoodWarners]

Thanks !

[bikendan]

Moved thread from the General Tech and Repair section to the Towing/Tow Vehicles sub-forum.

[Larry-NC]

Originally Posted by WildwoodWarners

Just picked up our used 2021 30KQBSS. We trailered our 2018 Springdale and traded up for this one.

On the way back with the new trailer the brake controller started saying Overload. It came and went on the way home then finally every time I hit the brakes it warned me.

I have read that newer trailers that have very little miles on them may need to adjust the brakes on the trailer. If that’s the case is it still possible that I would get an overload condition on the controller and not just soft breaks ?

There are two kinds of overload:

1. Trailer is too heavy
2. Too much current drawn by the trailer brakes

I'm guessing that it's (2). too much current drawn by the trailer brakes. There is possibly a short circuit in the brake wiring.

Each trailer brake has from 2.0 to 2.8 ohms resistance. That means that four brake assemblies measured together will measure 0.5 to 0.7 ohms. This will be a little tough to accurately measure with your everyday multimeter.

1. Set the multimeter to the lowest scale.
2. Turn it on.
3. Touch the two probes to each other.
4. Measure the resistance. You will subtract this number from subsequent readings.
5. Hold the trailer plug in your hand, facing you, with the rib up (at 12 o'clock).
6. Measure the resistance between the contact at 7 o'clock (brakes) and the contact at 6 o'clock (ground). These are the two contacts opposite the rib.
7. If the resistance (minus the original measurement) is less than 0.5-0.7 ohms, the brakes are drawing too much current.
8. First open the junction box where the trailer cable terminates.
9. The blue wire is usually brakes. Disconnect it.
10. Re-measure. The resistance should be infinity (blinking 1). If not, the cable is fault or the connector is wired poorly. (You can take the connector apart by loosening the strain relief and the tiny hidden screw on the side of the connector.)
11. If the resistance was infinity, look at the wiring going from the junction box to the four wheels for a pinched or crimped or chafed wire.
12. If none found, disconnect brakes at each wheel and measure each one, looking for 2 to 2.8 ohms.

Let us know how it comes out.

[WildwoodWarners]

Larry,

Seems like I have an interesting situation here.

At the 7-pin trailer connector measuring between the Brake “blue wire” and Ground “white wire” with all the brakes hooked up I get 1.1-1.2 ohms.

If I disconnect the “blue wire” in the junction box I get infinite, which is what I would expect.

I went to each brake and disconnected each of them and measured across the magnets. Below are the measurements.

Passenger Side Rear 3.0
Passenger Side Front 3.3
Driver Side Front 3.4
Driver Side Rear 2.9

Interestingly I did find a chafed wire on the Driver side rear as the wire went into the axel tub. So I cut that part out and reconnected all the wires back. I thoroughly inspected all other connections and wires for chafing and found nothing else.

Tested the brakes out again on a drive and within a few minutes I get the overcurrent warning and no brakes. I can pump them and the warning goes away and it will work normally for a bit longer. But always seems to come back.

Seems I only get the Overload or Brakes Shorted Warning from the Prodigy 3 if we are actually moving. If we are sitting still I can pull the leaver to Full even with the gain set to 14 and get no errors from the controller.

I feel like this points to some intermittent short somewhere but I’ve checked everything.

[IamProStreet]

Originally Posted by WildwoodWarners

I went to each brake and disconnected each of them and measured across the magnets. Below are the measurements.

Passenger Side Rear 3.0
Passenger Side Front 3.3
Driver Side Front 3.4
Driver Side Rear 2.9

Do the same but check to the ground of the trailer, frame or axle, should be open. If there is a measurement other than that the wire inside the drum is chafed.

[Larry-NC]

Truck wiring? Intermittent short in connector?

[Larry-NC]

Originally Posted by IamProStreet

Do the same but check to the ground of the trailer, frame or axle, should be open. If there is a measurement other than that the wire inside the drum is chafed.

I did find another source that suggested:

Originally Posted by eTrailer

For 7" brakes you should get 3.8-4.0 ohms, and for 10-12" brakes you should have 3.0-3.8 ohms.

Your readings aren't that far off. Now to start looking for an intermittent short someplace.

Just because it's easy, why not open up the connector first. Just loosen the strain relief clamp at the back and take out the tiny set screw on the side. Look for stray strands of wire or loose connections.

[WildwoodWarners]

Originally Posted by Larry-NC

I did find another source that suggested:

Your readings aren't that far off. Now to start looking for an intermittent short someplace.

Just because it's easy, why not open up the connector first. Just loosen the strain relief clamp at the back and take out the tiny set screw on the side. Look for stray strands of wire or loose connections.

Alright, thanks for all the help guys. Took me a bit to get back to working on the trailer.

I went through and opened resistance checked all the cables end to end. Tried moving stuff around and checking them again. Hoping to find the intermittent shorts. Found nothing but shows up immediately when driving around.

I also measured to ground all of the magnet wires as well and found no issues.

I decided to pull the drums off of each brake and inspect inside the wiring inside the drums. When I opened up the passenger side rear drum (of course the last one I tried) there it was. The magnet wire was very long inside the drum and had got itself twisted up near the shoes and had had several pinch points and chaffing. Looks like when the brakes engaged the wire would get pulled or pinched in the shoe pivot point and start to short out.

I replaced that magnet and put everything back together and all is right again !!!!!

Thanks everyone for the help !

[Larry-NC]

Originally Posted by WildwoodWarners

Alright, thanks for all the help guys. Took me a bit to get back to working on the trailer.

I went through and opened resistance checked all the cables end to end. Tried moving stuff around and checking them again. Hoping to find the intermittent shorts. Found nothing but shows up immediately when driving around.

I also measured to ground all of the magnet wires as well and found no issues.

I decided to pull the drums off of each brake and inspect inside the wiring inside the drums. When I opened up the passenger side rear drum (of course the last one I tried) there it was. The magnet wire was very long inside the drum and had got itself twisted up near the shoes and had had several pinch points and chaffing. Looks like when the brakes engaged the wire would get pulled or pinched in the shoe pivot point and start to short out.

I replaced that magnet and put everything back together and all is right again !!!!!

Thanks everyone for the help !

Good job! Congratulations!