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hex0rz

Trailer Brake controller

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Hey everyone! I got me a brake controller here. At first, it did not work right at all. I hooked up a trailer to tow a forklift and the lights never worked right. The wiring was all screwed up. I tried fixing it, and it still was not right. Even though I followed exactly what the instructions said. So I took it to a place and it took then like 3-4 hours to fix. Finally, everything was working!I towed a 24' travel trailer, all was well. Well, that was about a month or two ago. I noticed one day, that when I step on the brake pedal, the brake controller light does not come on? It did before after I paid to get it fixed! I checked the fuses, they are good. I have not screwed around with it since it was fixed. Anyone have any ideas?I believe it is one of those REESE controllers. If I hit the slider on the front, the light will light up. Is the controller still functioning or is something up?

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In my experience, the slider, button, what ever on the box is an over ride... bypasses the gradual application mode (if the brakes go "full on mode instantly, it's quite a jolt) & the over ride puts full power to the brakes. I'm not familiar with your unit... but since "it works" in over ride mode, what ever triggers it might have failed (brake pedal connection). Those lights are so you can tell if it's working. No light, no work! Since you paid to have it fixed, it ought to go back there.

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It has been a couple months since the repair job.. I dunno if they will still look at it without charging...

I have one of these:

Posted Image

I took the truck in because the trailer for the forklift did not work. Got it fixed, and they did not even have a trailer to go off of. When the time came to tow the trailer, I hooked it up, and it worked. A couple months later, which is about now, the light will not come on when I apply the brake. I have not had a trailer to try. I suppose I just need to get under the truck and look. I just did not know if someone knew about this sorta thing or not.

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Well basically that brake controller senses the brake pedal and then after that sense the amount of G force and calculates how much braking force (or voltage) to apply to the trailer brakes. With the manual slide pulled over is ther power on the brakes? Is the fuse blown for the controller?

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I believe the controller has 2 fuses. 1 is for the 12v constant to charge the trailer batteries, and 1 for the controller itself. When I push the manual slide over, the light does come on. But when I push on the brake pedal, the light does not come on.I believe, if I'm not mistaken, it splices into a wire under the dash. Whether or not it is for the brake pedal, I dunno. Guess I'm gonna have to check the wiring schematics.

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Are your truck brake lights working? Typically the electronic type trailer brake controler, reads the power on the truck brake light wire. It may depend on where your controler is mounted... mine is on the left knee panel... I'd open the door & just follow the wire. Earlier trucks required splicing (my old Chevy C30 required splicing... and running a brake wire to the back of the truck). In recent years, the trucks came prewired for trailers... It came with a pigtail which plugged into a rectangular socket in the harness down by the e-brake. It was a pretty easy install, splice the brake controler into the pigtail, plug the pigtail into the socket, plug the trailer into the OEM trailer plug (trailer package) under the bumper. I hope this helps you sort things out.Russell

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Russ is right about the pre-wired connector mine is also. The socket should be near the E-brake pedal. But being trailer brakes are electrical double check everything power wise and that the controller has power and its sending power to the trailer.

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I have the controller mounted on the panel right under the steering wheel. My brake lights are working. I will double check when I get a chance, though. I suppose I'm gonna have to open up the underside of the dash and give it a look.Testing whether or not the trailer is energizing the pin for the trailer brakes is just a matter of using DMM at the plug and seeing if it gives it 12v, right?

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Dropping the knee panel is no biggie. Very few screws along the bottom edge & then it'll pull off the spring retainers higher up. Mine is mounted on the panel to the left. You should be able to see the retangular trailer harness plug behind the e-brake without or before removing the panel & just follow the wires as far as you can toward your controler. If the controler leads go through the knee panel (my controler is to my left when seated & low enough that the leads go under the panel) you will likely have to drop it to confirm they haven't been damaged.

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Had the same problem with mine, wouldnt light up when i had a trailer plugged up but would when i hit the slider but either way the brakes didnt work. I unplugged the trailer and hooked a test light to a good ground and stuck it in the trailer brake hole. Went and hit the brakes and the brake controller was working fine and the test light would light up when i would hit the brakes so i knew it was on the trailer side, luckily it was a quick and easy fix (trailer brake wire pulled out of the plug on the trailer side.)-Jordan-

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Is your trailer plug factory wired on the truck side? If so it will include the ground. If not, look for a wire from the plug to the truck frame. Be sure the plug has a good ground. Then the same on the trailer side. The trailer's plug should be factory but doesn't mean it's not broke. A lot of small trailers have ground problems between truck & trailer. I've lost count of the intermittant light problems traced to the actual ground being through the ball & reciever.

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Hex what did you ever figure out with this? Im having the same problem with my trailer right now. Trailer brakes will not work with the brake pedal and the light on the controller wont change from green. But if I use the slide function of the controller the light changes from green to orange to red if I slide it all the way to the left and the brakes work as they should. I jacked the trailer wheels up and with the brake pedal hit there is absolutely no brake function to the trailer and I cant hear the magnets but when using the slider the wheels lock up and the magnets hum away. The same wiring is used to supply the trailer brakes so this kinda has me baffled why they wont work with the pedal. Its almost like I have the gain turned all the way down.

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your controller isn't getting the brake signal input from the truck. do your truck brake lights work? if not, bad brake switch. if so, bad wiring to the controller.

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I tested everything at the brake controller and when I step on the brake pedal Ive got almost 13 volts on the wire labeled "truck brakes" (at the controller) But on the wire labeled "trailer brakes" Ive got no volts when I step on the brakes. But if I use the manual switch on the controller and then the voltage will vary depending on how far Im pushing the manual switch which is how it should be I think? All lights on the truck and trailer work as they should. If its a wiring issue why do the brakes work when I use the manual switch on the controller? This is the part Im having a hard time understanding

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I thought maybe that was the case too so I swapped out the brake controller with a spare one I had. I have never used the other controller it was in a truck I bought for parts but its doing the exact same thing. Maybe I'll try to get my buddy over to hook his truck up to my trailer to see what it does. Thank you for the suggestions

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Tekonsha controllers they both appear to be the same model. I'm not sure what you mean by pendulum type but they both have a gain adjustment which acts kind of like a rheostat the more you turn up the gain the more voltage is applied to the trailers brakes. Both of them will activate the trailer brakes using the manual switch but when relying solely on the brake pedal it acts as if I've got the gain turned all the way down = no brakes. The last time I actually used the trailer back inJanuary the brakes worked just fine. A few weeks ago I pulled the hubs all apart to repack the bearings in ppreparation for the summer and a big road trip I'm taking the first weekend in May. I put the trailer back together and putt it up until the other day. I hooked up to it to haul dads tractor and that's when I noticed I didn't have any brakes. Thinking I messed something up when I had the drums off I took everything back apart but everything looks good inside. Like I said using the manual switch everything works properly. Its got me pulling my hair out

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Like I said using the manual switch everything works properly.

You didn't say what model, but my P3 kills everything when there's a short whether with the manual lever or automatic usage. Unless yours is different the above statement indicates to me you have a truck side issue not a trailer issue.

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There is no other name or numbers on the controller so Im not sure on the model. My buddy just bought a brand new truck last month lI'll get him over here in the next day or so and see what his truck does hooked to it. Thanks a bunch!

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The brake controller is not going to produce any signal from pressing the brakes when the truck is standing still. The lever might. I say might because each controller works differently when there isn't a trailer connected. It would help to understand how the controller works first. There are magnets in each electric drum and when you attach the trailer the brake controller measures the amount of resistance (number of magnets) and applies the correct voltage when needed. If the trailer is not connected the brake controller is not going to have any resistance and therefore may not produce a signal. If you are using electric over hydraulic it works differently. I doubt that is what you are using though.When you are moving and press the brakes the brake controller sense the amount of force applied and sends a signal to produce a signal in step with the amount of force it sensed. This is why you get nothing from pressing the brake when you're not moving.It would be best if you could hook up a trailer and test it.

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Yes I have done all this with the trailer hooked up and even ran down the road with it. But even sitting in the driveway when pressing on the brakes my controller will normally put voltage out to the trailer depending on where the gain is set. I can tell by the light on the controller it is green when connected and goes from orange to red as I adjust up to full gain. Now all I am getting is the green light showing the trailer is connected but it will not change like it normally will when I step on the brake pedal. I think that it is more on the trailer end because earlier I pulled the break away pin and I get nothing. Battery tested at 12.3 Volts and all connections tight so I think I need to change my troubleshooting from truck to trailer

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Most controlers get a signal from the brake light circuit (switch on the brake bracket, touches the pedal arm.) Confirm that the truch has brake lights. My truck had a trigger wire installed from the factory, there was a plug by the emergency brake & a harness that came with the truck. Older trucks were not so wired. Make sure how the controler is wired first. Unplug the trailer & test the rear socket with a meter. That said, there are often brake problems with trailers. Sometimes non-standard wired. Sometimes damaged or corroded wiring. The magnets themselves don't like to grab on rusted drums. Did these brakes combo ever work?

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All lights on truck and trailer function as they should. I am 99% sure it is a trailer issue because one of the last things I tried last night was to pull the break away pin (dont know why I didn't think of it before) and the brakes still do not function. I test the break away periodically and tested the battery last night as well. Magnets and contact surfaces on the drum as well as all other brake components are clean and in good conditiion. The last load I pulled before tearing the hubs down to repack the bearings worked fine and the next time after when I hauled my dads tractor is when I noticed they were no longer working. So to answer your question yes they have always worked prior to this. I have owned the trailer long enough to wear out a set of tires and do a brake job. I repack the bearings every year also and I didnt do anything differently than I have ever done in the past and I definitely Didnt touch the brakes other than to adjust the shoes up a little. I have not had time to look at it today hopefully tomorrow or the next day I can get back out and look at it. Got a big road trip coming up quick and I will be working some crazy hours the next 2. Weeks so I have to figure something out soon.

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