Trailer not recognized by brake controller

[Cantonio]

I have a new 5.0 brake controller work fine all the way from. Sumas to home. Today I wanted to take the trailer and to a park but noted that trailer is not recognized by brake controller. Any idea how to check wires? Thank you in advance. All lights work find.

[Centex]

Some relatively easy first suggestions for your consideration ....

• Check for dirt, debris, and moisture in the male and female sides of your 7-blade connector; dry* and clean is the order of the day. *A light coating of dielectric / 'bulb' grease may help once things are cleaned and dried (auto parts store item).
• Verify that the blades in the connector are making good contact - sometimes it can help to use a small / thin screwdriver to gently pry-open/apart the folded blades recessed in the connector to help them make good contact.
• Check all of the likely several fuses in your tow vehicle relating to trailer brakes. Refer to your vehicle Owner's manual, they may be spread among different fuse boxes in the vehicle interior or under the hood; there may be one or more 'inline' fuses depending on your brake controller installation.
• If you don't have one, find a 7-blade RV connector-tester that plugs into the socket on your vehicle, that can help determine if there's problem on the vehicle-side and thereby focus the troubleshooting on the vehicle or the trailer. Local auto-parts franchises often have them in stock, maybe Walmart, then there's always Amazon. It's a handy item to have in your toolkit anyway.
• With the trailer connector NOT plugged into the vehicle, pull-out the emergency 'brakeaway' lanyard on the trailer - either try to tow and see if the brakes are locked or listen carefully at each wheel for a 'hum' indicating the brakes are actuated. If they are, then the wires in the trailer to the brakes themselves are likely good. Reinsert the pin in the breakaway switch promptly when done. This should be a routine test of the breakaway system anyway.

Hope that helps, Good Luck!

[Cantonio]

The vehicle is not the problem, I connect the trailer to other trucks with brake control and none detect the trailer. Thanks for the response.

[C&G in FL]

What is your tow vehicle (manufacturer), and what other trucks have you connected to?

Even without knowing that, it would seem that you should check for continuity on the brake line between the umbilical plug and the contact at the rear of the hub. Have you tested the brakes by pulling out the break away switch (with the trailer’s house battery switch on)?

[TTMartin]

Originally Posted by C&G in FL

the trailer’s house battery switch on?

That may be the issue.

[Cantonio]

Originally Posted by C&G in FL

What is your tow vehicle (manufacturer), and what other trucks have you connected to?

Even without knowing that, it would seem that you should check for continuity on the brake line between the umbilical plug and the contact at the rear of the hub. Have you tested the brakes by pulling out the break away switch (with the trailer’s house battery switch on)?

No. Will do it today. The weird thing is that it work well from Sumas all the way home. It has been sitting for 2weeks and now it does not want to work with any changes made.

[Centex]

Originally Posted by TTMartin

That may be the issue.

While power from the trailer battery to the breakaway switch is necessary for breakaway operation (and the mentioned circuit tests), that has no effect on normal brake function via the tow vehicle brake controller, correct?

IOW, with or without power to the breakaway switch, the trailer should be detected and its brakes function via the TV brake controller.

Given updates, my next thought would be to gain access to the junction box at the trailer-end of the umbilical cable (sorry, not sure its location, follow the umbilical cord) and see if anything has come loose in there. From that box one can do a continuity test from the end of each umbilical wire to its corresponding blade in the connector to see if there's been a fluke failure within the umbilical cable.

[Bobbie54]

I had a problem on my 15- the 7 way connector didn’t allow the connection to be very good with the tow vehicle. I forget the brands now but like yours, mine worked for awhile and then didn’t. I verified that the brake connection was live from the tow vehicle but what was happening was the connector on the trailer side was too loose. I ended up changing the receptacle on the tow vehicle side but I still had to be very careful.

The one on my Ridgeline see,s to keep a good connection and locks in place better, but I don’t know what it will do if it loosens up.

[TTMartin]

Originally Posted by C&G in FL

the trailer’s house battery switch on?

Originally Posted by TTMartin

That may be the issue.

Originally Posted by Centex

While power from the trailer battery to the breakaway switch is necessary for breakaway operation (and the mentioned circuit tests), that has no effect on normal brake function via the tow vehicle brake controller, correct?

Maybe, Maybe not. It may be necessary for your brake controller to register normal operation. If your brake controller doesn't see power back on the power pin, it may assume there is no battery connected and therefore no emergency brake away brake available, so as a safety it doesn't pass the normal operating check.

But, given that sounds like something you might have changed since the trip back from Sumas, and it is an extremely simple thing to check, it is where I would start.

[Centex]

Originally Posted by TTMartin

Maybe, Maybe not. It may be necessary for your brake controller to register normal operation. If your brake controller doesn't see power back on the power pin, it may assume there is no battery connected and therefore no emergency brake away brake available, so as a safety it doesn't pass the normal operating check.

Sorry, but a brake controller has no way of sensing the presence / absence of current across an open breakaway system circuit. Other than the few 'wireless' controllers none are connected to the 'power pin' on the trailer umbilical or vehicle socket, so they can't sense the presence or absence of current on that circuit either.

With the breakaway pin inserted for travel that breakaway circuit is 'open' with no link whatsoever to the in-vehicle brake controller; it's as if that breakaway system doesn't exist at all; there's no way for the in vehicle controller to 'test' that for proper operation (or even power to that breakaway system), nice though that might be if it could.

It'd be a poor design indeed if normal controller-actuated braking were inhibited in any way by loss of power to the breakaway system or trailer battery power in general; thus none do that.

[TTMartin]

Originally Posted by TTMartin

Maybe, Maybe not. It may be necessary for your brake controller to register normal operation. If your brake controller doesn't see power back on the power pin, it may assume there is no battery connected and therefore no emergency brake away brake available, so as a safety it doesn't pass the normal operating check.

Originally Posted by Centex

Sorry, but a brake controller has no way of sensing the presence / absence of current across an open breakaway system circuit.

That's not what I said. I said it might take the lack of a power return on the power pin an indicator that the trailer doesn't have a battery installed, which it may interpret as being a necessary component of the emergency break away brake.

[Centex]

Originally Posted by TTMartin

That's not what I said. I said it might take the lack of a power return on the power pin an indicator that the trailer doesn't have a battery installed, which it may interpret as being a necessary component of the emergency break away brake.

Your selective clip from my post failed to capture my full response to your suggestion. In any case, probably time to move on from this tangent to the thread.

[TTMartin]

Originally Posted by Centex

Your selective clip from my post failed to capture my full response to your suggestion. In any case, probably time to move on from this tangent to the thread.

There was nothing in the rest of your reply that changes what I said.

Originally Posted by Centex

Sorry, but a brake controller has no way of sensing the presence / absence of current across an open breakaway system circuit. Other than the few 'wireless' controllers none are connected to the 'power pin' on the trailer umbilical or vehicle socket, so they can't sense the presence or absence of current on that circuit either.

With the breakaway pin inserted for travel that breakaway circuit is 'open' with no link whatsoever to the in-vehicle brake controller; it's as if that breakaway system doesn't exist at all; there's no way for the in vehicle controller to 'test' that for proper operation (or even power to that breakaway system), nice though that might be if it could.

It'd be a poor design indeed if normal controller-actuated braking were inhibited in any way by loss of power to the breakaway system or trailer battery power in general; thus none do that.

Originally Posted by TTMartin

That's not what I said. I said it might take the lack of a power return on the power pin an indicator that the trailer doesn't have a battery installed, which it may interpret as being a necessary component of the emergency break away brake.

You can try to find something else to blame, because you don't think having the brake controller check for someone trying to tow with no power available for the emergency breakaway controller is a good idea. Or you could try connecting your trailer battery. I know what I'd do.

[Dave Walter]

My Tekonsha Prodigy RF controller requires 12V power from the TV to the trailer in order to operate the controller. Of course, this is a bluetooth controller!

[Brian B-P]

Originally Posted by Centex

Sorry, but a brake controller has no way of sensing the presence / absence of current across an open breakaway system circuit. Other than the few 'wireless' controllers none are connected to the 'power pin' on the trailer umbilical or vehicle socket, so they can't sense the presence or absence of current on that circuit either.

That's a good point - no in-tow-vehicle controller will "know" or care about the existence of a battery in the trailer. Even it if were connected to the +12V contact of the towing connector (and they're not), it would see voltage from the tow vehicle whether there was a trailer battery or not, so it would still have no way to detect the existence of a battery in the trailer.