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WV Ridge Runner
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Discussion Starter · #1 ·
Hello,
I purchased a 33.5’ TT back in May. When I went to establish the gain for the TT brakes, I did the usual and found a flat road with no traffic, at 20-25 mph squeezed the levers together on the trailer brake controller and at 10 gain the truck/trailer barely slowed. I replaced a blown fuse in the truck that affected the marker lights on the TT and had to still take it to the Ram dealership when the new fuse didn’t work. They told me they had to reset the computer (Didn’t make sense). But I told them about the above brake controller issue and they said everything checked out. Took the TT to the dealership today to have the brakes adjusted. They did a little adjustment, but the guys showed me when they hooked up a trailer brake meter to my truck. At 10 gain and the brake controller levers squeezed together showing 100%, the truck is sending only 6 volts to the trailer for braking. The service guys said that should be 11-12 in brake voltage.
Went back to the Ram dealership and showed them the attached photo and explained this to them. Their response was the OEM trailer brake controllers can’t be adjusted and it wasn’t the first time they’ve seen this issue. Their plan is to hook up with their meter to confirm and call the Tech helpline to see if anything can be done. So with the TT brakes adjusted, it’s better and slows down but it’s not what it should be IMO. I should be at around 5-6 gain and the TT brakes should dang near lock up at 10 gain. Anyone familiar with this and a potential solution? I haul the TT and occasionally a gooseneck with tractors and want the trailers to work as hard as the truck to get stopped if I have to lock it up. Thanks and take care. Happy 4th!
Automotive tire Motor vehicle Finger Gas Engineering
 

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This has gone on for years. Ram claims the controller is performing as designed. Because it’s tied into the anti skid/ anti lock system it pulls voltage from the trailer brakes below about 35 mph. The only fix I’ve found is an aftermarket controller. Unplug the factory module located behind the lower dash behind your right knee and plug it into the aftermarket unit using the recommended adapter harness.
 

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What controller setting are you using? Try both, light and heavy.
 

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Been there, done that. Once the truck speed goes over 35 mph the voltage increases.
That very well may be so, however, I would not ever go back to an aftermarket controller in my '21. It works better than a Kelsey Hayes. I use (3) empty trailer and 5-6 loaded. This is with the controller on light electric. I have no feeling of low brake power at low speed, such as in town or slow off highway use. If I forget to turn down the setting after I dump, the first thing that happens, is, locked up trailer tires on brake application. Mine works fine.

One thing I have noticed, is, when I buy a new trailer, the brakes seem to need "broken in" before they work really well.
 

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The OP didn‘t list the year of his truck but I’d bet a farm out west it’s not a 21. I do know later model year trucks use a different part # ITBM and they are not compatible with 15-18 build dates.
The trouble began in 15 when they first incorporated anti skid/ anti lock technology in the ITBM. Their strategy was as I’ve described. Pull voltage at low speed so. You can’t lock the trailer brakes. It’s obvious the engineers have never pulled a 20K trailer into a downhill 4 way stop. The factory controller in my truck will fail the state inspection test for failure to lock the trailer brakes using the manual lever at a stop, just as the OP described. The breakaway switch locks the brakes as does the manual lever on my aftermarket controller, proving the trailer brakes aren’t at fault. I’d prefer a factory controller if it worked but stopping is my real priority.
 

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The PO's signature says he has a '21 2500, same as mine. Maybe they improved them in 19+?
 

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Your right, I didn’t notice that, I’m out one farm out west. That doesn't change the reading he’s shown us on the trailer check box. Your not going to get proper braking on 1/2 the available voltage, and as I’ve previously posted and he’s confirmed, Ram says there’s nothing wrong.
 

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OP, did you get the Z20 recall and have it done? It is in reference to the Electronic Stability Control/Anti-Lock Brakes. May be related to your issue?
 

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WV Ridge Runner
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Discussion Starter · #10 ·
I appreciate all the replies, so if I understand what you fellas are saying the voltage increases with speed? So if I’m traveling 55mph and slam on the brakes, the OEM trailer brake controller will send more voltage and lock up the trailer brakes? And if this is the case then what do I set the gain to when towing? Do I put it on 10 gain for every trailer and towing situation? I want to figure this out and I’m afraid as @Jhenderson has indicated, there’s no fix. Not sure if I wanna waste my time and drop it off at the dealership this week.
 

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The test I performed utilized a DVM wired to one truck side trailer connector while my trailer was hooked to the other. I drove at various speeds with someone watching the DVM. Below 30-35 mph with the gain set to maximum, the max voltage applied by either foot brake or manual application was just over 6 volts. Above 35 mph the voltage increased until approximately 50 mph where 12 volts were witnessed being applied to the trailer brakes. I can’t tell you what to do, only what i found 7 years ago and how I dealt with it.
 

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Discussion Starter · #13 ·
What controller setting are you using? Try both, light and heavy.
This is the only thing I wished I would’ve done while the RV dealership had the trailer brake voltage meter hooked up, was change it from light electric to heavy electric and see if that made a difference. So my TT is just under 8K lbs, the manual says under 10K set to light electric and over 10K set to heavy electric.
 
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Have you tried any other trailer? There are multiple threads about this issue on the pre '19 trucks, including info from JH. Some have used heavy hydraulic with good results. Read the first thread at the bottom of this page.

Just guessing, but if my dump only requires a gain of 3 empty and 5-6 loaded, it needs way less than 12 volts to stop. I will test mine stopped in the yard and see what kind of volts I get with several different settings and post back.

When I am maneuvering (forward and back) at real slow speed to set up a dump location, I have to turn my controller down or it is too severe.
 

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This is my voltage reading at 3-6 and 10 gain. About the same as yours. This is parked, with the dump trailer attached and the engine idling, at the bumper plug. Apparently, the voltage is enough for my dump trailer. Like Ram says, yours is probably working as it should:)

Trailers and brakes are not all created equal. Wiring/size, magnets and brakes are all over the place. My dump is 22k, so it has large brakes, wire and magnets. I have not pulled my small trailer with 3500 lb axles yet. It might not work as well.....

Gas Font Electronic device Display device Machine
Motor vehicle Font Gas Electrical wiring Auto part
Motor vehicle Bumper Automotive exterior Gas Display device
 
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