2024 Brake controller Problems

[mjonesjr84]

4 minutes ago, Chadw90 said:

On the 12v wire. I bought a short extension cord, opened it up and installed a diode inline on the 12v wire

Didn't work for mine. I installed the hydrostar modules on both the 12 volt positive and the brake wire as suggested by hydrostar and my GM dealer. When I left this past Wednesday for an 8 hour trip with the trailer RV still did the brake disconnection went hard on the brakes, when I needed them the most. I forgot the 2022 module that I have at home or I would have swapped that in.

 

There is zero reason for the brakes to disconnect. Even if there is a problem with the trailer brakes the truck shouldn't disconnect. I see it as a major safety issue.

Edited October 5, 2025 by mjonesjr84

[Chadw90]

2 minutes ago, mjonesjr84 said:

Didn't work for mine. I installed the hydrostar modules on both the 12 volt positive and the brake wire as suggested by hydrostar and my GM dealer. When I left this past Wednesday for an 8 hour trip with the trailer RV still did the brake disconnection went hard on the brakes, when I needed them the most. I forgot the 2022 module that I have at home or I would have swapped that in.

 

There is zero reason for the brakes to disconnect. Even if there is a problem with the trailer brakes the truck shouldn't disconnect. I see it as a major safety issue.

My problem was/is different than yours i guess. Yours is disconnecting, mine is dropping amperage as it seeing the trailer battery reach almost 13v’s. 
Once I put the diode inline, it prevented back-feeding and tricked the truck. 
My symptoms were strong brakes at the start and once the battery got charged up, Id have to turn the brake controller to 10 to get it to slightly grab the brakes. Most people wouldnt notice as they dont  periodically just check their brakes along the trip. The symptoms are same as brake fade, but it happens with every trailer of all configurations. 
Like you, Im not impressed. When I go to buy a new truck, if GM hasnt rectified this, I may entertain a Ford, possibly a (gulp) Dodge. 

[mjonesjr84]

1 minute ago, Chadw90 said:

My problem was/is different than yours i guess. Yours is disconnecting, mine is dropping amperage as it seeing the trailer battery reach almost 13v’s. 
Once I put the diode inline, it prevented back-feeding and tricked the truck. 
My symptoms were strong brakes at the start and once the battery got charged up, Id have to turn the brake controller to 10 to get it to slightly grab the brakes. Most people wouldnt notice as they dont  periodically just check their brakes along the trip. The symptoms are same as brake fade, but it happens with every trailer of all configurations. 
Like you, Im not impressed. When I go to buy a new truck, if GM hasnt rectified this, I may entertain a Ford, possibly a (gulp) Dodge. 

Yea that's different.

 

I've read the new Rams have the same problem. I hate the Ford interior. 

[mjonesjr84]

If I restart the truck, the brakes will come back on until I use them again. 

 

My trailer TPMS sensors keep going in and out as well.

[Chadw90]

3 minutes ago, mjonesjr84 said:

If I restart the truck, the brakes will come back on until I use them again. 

 

My trailer TPMS sensors keep going in and out as well.

Get what you pay for I guess. Should have bought the Denali Ultimate for $130,000k CAD. Shame on me for buying the poverty AT4 for $106,000 lol. I should have kept my 2017, enough technology to keep you happy and not enough to have little gremlins like this. Id be tempted to go back to a 2017-2019 if I could find some gem that was just a sunday truck and low miles. 

[mjonesjr84]

1 minute ago, Chadw90 said:

Get what you pay for I guess. Should have bought the Denali Ultimate for $130,000k CAD. Shame on me for buying the poverty AT4 for $106,000 lol. I should have kept my 2017, enough technology to keep you happy and not enough to have little gremlins like this. Id be tempted to go back to a 2017-2019 if I could find some gem that was just a sunday truck and low miles. 

My brother's 21 and 22 3500s that he owns doesn't do this with my trailer. 

[bruceb58]

13 hours ago, Chadw90 said:

My problem was/is different than yours i guess. Yours is disconnecting, mine is dropping amperage as it seeing the trailer battery reach almost 13v’s. 
Once I put the diode inline, it prevented back-feeding and tricked the truck. 
My symptoms were strong brakes at the start and once the battery got charged up, Id have to turn the brake controller to 10 to get it to slightly grab the brakes. Most people wouldnt notice as they dont  periodically just check their brakes along the trip. The symptoms are same as brake fade, but it happens with every trailer of all configurations. 
Like you, Im not impressed. When I go to buy a new truck, if GM hasnt rectified this, I may entertain a Ford, possibly a (gulp) Dodge. 

Do you have an EOH system or magnet electric brakes?

[mjonesjr84]

8 hours ago, bruceb58 said:

Do you have an EOH system or magnet electric brakes?

Magnetic drum brakes.

[bruceb58]

2 hours ago, mjonesjr84 said:

Magnetic drum brakes.

I was asking the other guy.

 

Thought you had the EOH Hydrastar system!

[mjonesjr84]

12 minutes ago, bruceb58 said:

I was asking the other guy.

 

Thought you had the EOH Hydrastar system!

No. I talked to Hydrastar and they recommended their module for the electric drum brakes, even the dealer printed off a GM recommendation for the Hydrastar modules.

[Chadw90]

On 10/5/2025 at 9:44 PM, bruceb58 said:

Do you have an EOH system or magnet electric brakes?

Magnet brakes here too. Electric hydraulic discs would be cool though 

[bruceb58]

21 hours ago, Chadw90 said:

Magnet brakes here too. Electric hydraulic discs would be cool though 

Have you ever checked the voltage going to the brake magnets by comparing when the truck is running vs engine off? Of course you would just push the manual lever to perform this test.

 

I would think the voltage being sent to the magnets would be independent of battery voltage.

 

Another thing, Have you ever burnished your brakes? When I bought my trailer, I had to have the gain very high until I burnished the brakes. Then I could run at a gain of 6 where it required 9 before.

 

Edited October 8, 2025 by bruceb58

[Chadw90]

Yes I have. Battery voltage at brakes with controller on 10. 
once the trailer battery was fully charged, the brake voltage remains the same, but amperage drops through the floor. I can pull 10 different models of new trailer out of the lineup (we sell trailers at my work) or 10 used trailers, all the same until i put the diode inline. 
try to explain voltage vs amperage to a dealership auto mechanic is like trying to explain colors of the leaves in fall to a color blind person. Just doesn’t resonate lol. 
Not sure why something like a trailer brake controller needs to be over engineered by running it through it’s own logic controller, what was wrong with 12V direct battery wire to brake controller to brakes. 

 

[mjonesjr84]

9 minutes ago, Chadw90 said:

Yes I have. Battery voltage at brakes with controller on 10. 
once the trailer battery was fully charged, the brake voltage remains the same, but amperage drops through the floor. I can pull 10 different models of new trailer out of the lineup (we sell trailers at my work) or 10 used trailers, all the same until i put the diode inline. 
try to explain voltage vs amperage to a dealership auto mechanic is like trying to explain colors of the leaves in fall to a color blind person. Just doesn’t resonate lol. 
Not sure why something like a trailer brake controller needs to be over engineered by running it through it’s own logic controller, what was wrong with 12V direct battery wire to brake controller to brakes. 

 

1000%.

 

I actually got mine fixed yesterday and not by the dealer. I spent 30 minutes under the trailer testing each magnet (6) resistance. When they checked good, I decided to rewire the brakes from where the blue wire comes out of the harness at the axles. I eliminated each individual crossover in the axles with 1 cross over. I used 10AWG wire. Hooked the truck up, tested the brake switch in the driveway and got no disconnect. So I hooked the trailer up and drove it about 10 miles across town and back with no issues. 6 trailer brakes with a truck/trailer weight of 24k is nice. 

 

I don't understand why it would disconnect in my 25 but not my brothers 22. I can't believe GM hasn't been sued for a wreck. Even if there is an issue, an old fashioned trailer brake controller would still power through and work.

[Chuck FB]

4 hours ago, mjonesjr84 said:

1000%.

 

I actually got mine fixed yesterday and not by the dealer. I spent 30 minutes under the trailer testing each magnet (6) resistance. When they checked good, I decided to rewire the brakes from where the blue wire comes out of the harness at the axles. I eliminated each individual crossover in the axles with 1 cross over. I used 10AWG wire. Hooked the truck up, tested the brake switch in the driveway and got no disconnect. So I hooked the trailer up and drove it about 10 miles across town and back with no issues. 6 trailer brakes with a truck/trailer weight of 24k is nice. 

 

I don't understand why it would disconnect in my 25 but not my brothers 22. I can't believe GM hasn't been sued for a wreck. Even if there is an issue, an old fashioned trailer brake controller would still power through and work.

The further they forge ahead and invent complexity the further we fall behind !. 

 

So you had gone through the positive side of the braking system replacing wires and that for some reason made the trucks system happy, I was wondering what the condition of the negative side of the wiring system is in. Its been so long since I have looked at how they tend to wire up trailers to ground the axle hub I just don't know how elaborate or pathetic they create the negative path. Obviously your negative side is doing well enough to allow the brakes to function but why I asked how healthy it appears to be and if they run the negative from the hubs just to the frame and rely on grounding contact there and near the hitch the negative grounds there for the trailer plug ?.