Trailer Brake controller

[hex0rz]

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?

[Mopar1973Man]

You might go back t othe guys again that did the work. Maybe the change the truck to work the fork lift and now doesn't work the travel trailer...

[flagmanruss]

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.

[hex0rz]

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:

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.

[Mopar1973Man]

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?

[hex0rz]

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.

[flagmanruss]

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

[Mopar1973Man]

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.

[hex0rz]

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?

[flagmanruss]

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.

[MarbleCrusher]

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-

[flagmanruss]

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.

[diesel4life]

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.

[mr.mindless]

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.

[diesel4life]

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

[mr.mindless]

that's easy: controller is shot, then.

[diesel4life]

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

[mr.mindless]

:cookoo:what sort of brake controllers are these? are they set properly as far as level goes if they are pendulum type?

[diesel4life]

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

[mr.mindless]

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.