Trailer Brake problem, constant voltage on Brake wire

[MIDNIGHT RIDER]

Yeah, I told the shop that I am dropping the truck off to that I think the truck needs to be rewired. My appointment is on Wednesday the 28th.

Just the thought of some "shop" messing with the wiring in my trucks/trailers ties knots in my stomach.


I just about re-read this entire thread and still stick with one of my prior statements.

On most all "modern" electronic controllers, there is a little green indicator light which remains un-lit when no trailer is connected.

Plug a trailer in and that little green light will come on.

Push the brake-pedal and that green light turns red, often followed by a string of red dots; more dots with more brake application.

The ONLY way that controller knows a trailer is connected is via that weak low-voltage passing through the magnets to GROUND.

Whenever a test-light or volt-meter is put to the BRAKE wire, the test light or volt-meter then becomes the path to GROUND and will read that low-voltage signal.

The four or so volts should not be enough to activate the magnets into pulling against the hubs.


Then again, I could be wrong, not because I don't know what I am talking about, but because I am not personally looking at the set-up you are having problems with.




I have said it a million times before, electric brakes are a joke.

 

[racer30]

If the trailer has a molded on plug its probly ok, look under the trailer where the 7 way wire enters the belly of the trailer. Some trailers have a junction box under a panel in the floor. If the trailer has a replacement end look inside it for a problem. New controllers send power out to look for the magnets on the trailer, thats how it senses the trailer is conected to the truck. If you use a meeter on the wire you will see power out the brake wire from the controler, this is normal. If you use a test light you will see the light go from dim to bright as someone moves the manual control lever on the brake control. Make sure the shop show's you how they found the problem and how they repaired it before leaving the repair shop.

 

[cardana24]

Just the thought of some "shop" messing with the wiring in my trucks/trailers ties knots in my stomach.


I just about re-read this entire thread and still stick with one of my prior statements.

On most all "modern" electronic controllers, there is a little green indicator light which remains un-lit when no trailer is connected.

Plug a trailer in and that little green light will come on.

Push the brake-pedal and that green light turns red, often followed by a string of red dots; more dots with more brake application.

The ONLY way that controller knows a trailer is connected is via that weak low-voltage passing through the magnets to GROUND.

Whenever a test-light or volt-meter is put to the BRAKE wire, the test light or volt-meter then becomes the path to GROUND and will read that low-voltage signal.

The four or so volts should not be enough to activate the magnets into pulling against the hubs.


Then again, I could be wrong, not because I don't know what I am talking about, but because I am not personally looking at the set-up you are having problems with.




I have said it a million times before, electric brakes are a joke.

I know, I am just to the point that I want it to work and I am tired of spedning hours and hours on it just to have the same results. I work two jobs and now that the days are shorter and colder it hard to get motivated when it's already dark and cold out when I get home, and the truck will not fit in my small garage. I am not familiar enough with electic brakes to know how much voltage should be coming though the line at any one time. I know that as the voltage goes up the braking power will increase...and mine does increase when the brake pedal is pushed.

If the trailer has a molded on plug its probly ok, look under the trailer where the 7 way wire enters the belly of the trailer. Some trailers have a junction box under a panel in the floor. If the trailer has a replacement end look inside it for a problem. New controllers send power out to look for the magnets on the trailer, thats how it senses the trailer is conected to the truck. If you use a meeter on the wire you will see power out the brake wire from the controler, this is normal. If you use a test light you will see the light go from dim to bright as someone moves the manual control lever on the brake control. Make sure the shop show's you how they found the problem and how they repaired it before leaving the repair shop.

I will. They have been around for a long time and have a good reputation, the same people have worked their for ever so hopefully they can figure it out.