Symptoms of Bad Breakaway Switch?

[Kevin A]

After 9 weeks in the RV repair shop this summer and a full new set of brake components, mostly new wiring, and a bundle of $$, we got a call from the shop that our trailer was ready. On hookup, however, the P3 controller showed no trailer attached. The TV and controller test fine when plugged to another trailer. The shop is now saying the breakaway switch is probably the culprit. Will a bad switch cause the controller to not see the trailer? I'm afraid they're starting to guess now! The lights all work when plugged into the TV, so there is power from the TV. However, the trailer battery needs a charge, so could that impact the breakaway switch and controller reading, too? Thanks.

[Raspy]

The breakaway switch should not make the trailer invisible to the controller because all it does is connect the battery to the brake magnets when the cord is pulled. It's easy to test, just pull the cord and see if the brakes go on.

If the brake controller cannot detect the trailer, it probably means there is a problem with the brake circuit. This could be a bad ground where the ball is acting as the ground and working well enough to work the lights, but still being a bad connection. There needs to be a good circuit from the brake controller to the magnets and back to the TV with a dedicated ground wire. The brake negative, or ground, has to go to the trailer frame, or the trailer ground wire and the frame. The brakes can't ground reliably through the suspension system.

Might be a wire on the wrong plug terminal, or a bad ground.

I don't know why it would take nine weeks to do the described work and not be able to troubleshoot a simple problem, while just guessing at an unlikely reason. Sounds like you are not getting good treatment.

[Joe Romas]

The break away switch has two wires. One is connected to the BLACK plus wire in the 7 pin pigtail that supplies, charges, 12 volts to the trailer battery.
The second wire connected to the BLUE wire in the pig tail that goes to the brake solenoids.

Under normal conditions the break away switch does not connect these two wires to together.

When the pin is pulled the break away switch switches the black and blue leads together supplying voltage to the brake solenoids.

You don't say if the trailer is new to you or if the brakes ever worked so who knows??

So yes it's possible that a completly good switch IF the battery is connected backwards and the pin is pulled

On most RV's the black lead is positive and the white lead is ground. But people familiar with automobiles relate BLACK to ground and RED to positive.

My suspicion is the battery is connected backwards

For a quick test you could disconnect and isolate boths wire from the battery the battery and

[gordon2]

You brake power circuit is separate from the lights so having lights in the camper when you are hooked to the tug is meaningless.

The trailer battery (or a separate break-away switch battery) is used for the brakes when the break-away switch is activated but is otherwise not involved in the brakes. Is it dead because they pulled the switch and left it on? That will kill a battery pretty quick. But that would not cause the P-3 to complain.

You tested the tug and controller on another vehicle so we can rule that out. Simply disconnect the break-away switch altogether and try again. Then you can prove to the shop that they mucked it up, since the break-away switch need not be present for the brake system to work.

It really does sound like the shop is incompetent.. I hope you have not paid them yet. Time for a new shop I think.

[Kevin A]

Thanks to all. The brakes did work for about two weeks in June after all new brake components were installed on the twin axles (after 3 weeks in the shop). Then, they abruptly quit while on a 1800 mile round trip to Philadelphia in mid-June. When I returned it to the shop, it sat for 4 weeks before they said I had some bad old brake wiring under the trailer. They replaced these wires and called me to pick up the trailer on Aug. 3., saying everything tested good. I went to pick it up, paid the bill before I could have it back, and hooked up. No signal to controller. One of their techs came out to the lot, got a good test light signal when jumping across the breakaway switch connections, and declared the switch as the culprit. After a week, they called to say the wrong breakaway switch was sent to them and they are re-ordering. I really thought those were pretty interchangeable. My suggestion was to bypass the breakaway switch just for test purposes to see if the controller came to life and they kind of acted like my opinion was cockeyed. I do think the switch could be bad and stuck closed, causing the battery to drain. But I don't know about the lack of signal to the controller.

[gordon2]

Originally Posted by Kevin A

..I do think the switch could be bad and stuck closed, causing the battery to drain. But I don't know about the lack of signal to the controller.

Just disconnect it. Get an ohm meter and check the switch. Disconnecting it is the most basic of trouble shooting steps the shop should take if they suspect its bad. Thousands of trailers with electric brakes dont even have break-away switches. I'm not saying not to use one, esp if its a legal requirement, but for now just eliminate it. If the P-3 still says "no trailer" then find a competent shop.

[floyd]

I didn't read all the above, so forgive me if I missed something...
In 50 years of automotive work I have found that most problems are bad grounds. Check the grounds for the trailer brakes.
Also look to see if they are wired directly to the frame or if butt splices are used.
There should be three points of ground on a typical installation...
One at each brake and one in the plug harness, probably at the tongue.


Not sure on your Bigfoot so an alternative may be that the brakes are not grounded to the frame but hard wired all the way back to the plug harness which would work just as well.

[Joe Romas]

Originally Posted by floyd

...
There should be three points of ground on a typical installation...
One at each brake and one in the plug harness, probably at the tongue.

On my Casita the brakes are only connected to the WHITE negative/common lead and the BLUE brake leads inside the 7 pin cable.
The only place the frame and common leads are connected are on the battery where the white and green wires are on the negative battery terminal.

Personally I think it's time to bite the bullet and find another mechanic:

[Kevin A]

Brief update: Spoke with a person higher up in the organization yesterday and it seems the service manager has been let go. I filled in the "new" guy about the situation and it seems they are going to expedite our repair this week. I still have concerns about their head electrician who feels that a bad breakaway switch could be fooling the P3 controller. I asked them to just disconnect the current switch and to test for good continuity in the circuit, especially looking for a bad ground in their new wiring job. We'll see what happens.

[CindyL]

Well, well, well. The RV company changed the breakaway switch; no difference. Still no signal to the brakes, although our Expedition brake controller will connect to other campers parked on their lot. Interesting that they did not call us that it was finished. They must have tested it and discovered that like Kevin told them, it did not work Kevin went to pick it up today, regardless. The nice ladies in the front were told that our grandkids want to camp next week, so it was coming home. And it is home. My review of this company is being developed and will be posted on Google, Yelp, and anywhere else that it seems appropriate.


CindyL

[WizWid]

I think its time for you to start over.
Each electric brake consumes about 3A.
So your 4 brakes in parallel should pull about 12A
Therefore the resistance on that circuit should be about 1 ohm to ground.

Pull out your 7 pin plug and measure the resistance from the "brakes" pin to ground. What does yours measure?

[Joe Romas]

Jim

Unfortunately some people don't have the ability or facilities to simply rewire the brakes from the 7 pin to the wheels and must depend on others.
I feel sorry for them. Once the problem was solved the solution will turn out to be something simple

[gordon2]

Originally Posted by widgetwizard

I think its time for you to start over.
Each electric brake consumes about 3A.
So your 4 brakes in parallel should pull about 12A
Therefore the resistance on that circuit should be about 1 ohm to ground.

Pull out your 7 pin plug and measure the resistance from the "brakes" pin to ground. What does yours measure?

+1 (but just to be clear, thats on the trailer's plug with the tow vehicle not connected. and leave the break-away switch OPEN or disconnected also).

I get the impression that OP did not want to try and troubleshoot this themselves, esp. after spending a bunch of money to hire someone to do the work. But if you want something done right.. sometimes you have to do it yourself. So this is a good thing to check. You can also pull the drum and check the magnet directly, and test the wiring from the brake magnets to the plug.

etrailer says that the 7 inch brake magnet resistance should be 3.8-4.0 Ohms
10 and 12 inch brake magnets resistance should be 3.2-3.5 Ohms. So you are looking for low resistance. I'll bet you get infinite resistance instead, or perhaps some very high value... high enough (or infinite) so that the P3 thinks there is not trailer connected. Perhaps its something as simple as a bad crimp in the new wiring, but it should not be hard to diagnose by anyone who does trailer or vehicle wiring frequently or as a profession. So I cant wait to read the review.

[CindyL]

Originally Posted by Joe Romas

Jim

Unfortunately some people don't have the ability or facilities to simply rewire the brakes from the 7 pin to the wheels and must depend on others.
I feel sorry for them. Once the problem was solved the solution will turn out to be something simple

If you read this before my edit, Joe, my apologies. I read your comment too fast. We paid them almost or more than 3000 dollars to get these brakes working. The first time they gave it to us with the declaration that it was fixed, we drove back from New Jersey with no brakes, as they failed, and our Bigfoot is 28 feet with lots of interior oak, not a light thing. The next time they said it was done after rewiring the brakes. Kevin tested the brakes before it left the lot. Needless to say, it stayed there.

Our grandkids expect to camp next week. Even if it is in our driveway, they will camp.

Kevin is going to borrow the neighbor's jack, add ours, and buy another to see if he can fix it himself. Trouble is, school starts for both of us too. I had planned on him adding something to raise our porcelain toilet and put in new flooring this summer (We have the parts.), but it sat at this inept RV place all since June!

And yes, I think it is a simple solution, but I feel much better that it not be done by them. I am sure Kevin can do it, although now time is at a premium. Happily, we had no specific plans other than the grandkids for a bit, and they will be thrilled if we just camp in the driveway. We had to skip our usual trip to Algonac this year, as our daughter bought us Cubs tickets that weekend. No specific plans after that. I have an ungodly fall semester.

CindyL

[CindyL]

Originally Posted by gordon2

+1 (but just to be clear, thats on the trailer's plug with the tow vehicle not connected. and leave the break-away switch OPEN or disconnected also).

I get the impression that OP did not want to try and troubleshoot this themselves, esp. after spending a bunch of money to hire someone to do the work. But if you want something done right.. sometimes you have to do it yourself. So this is a good thing to check. You can also pull the drum and check the magnet directly, and test the wiring from the brake magnets to the plug.

etrailer says that the 7 inch brake magnet resistance should be 3.8-4.0 Ohms
10 and 12 inch brake magnets resistance should be 3.2-3.5 Ohms. So you are looking for low resistance. I'll bet you get infinite resistance instead, or perhaps some very high value... high enough (or infinite) so that the P3 thinks there is not trailer connected. Perhaps its something as simple as a bad crimp in the new wiring, but it should not be hard to diagnose by anyone who does trailer or vehicle wiring frequently or as a profession. So I cant wait to read the review.

Kevin and I thought it would be a fairly simple fix. With limited time and limited jack capacity, we thought an experienced RV place would have it fixed quickly with minimal cost. Costly lesson, I guess. I feel much better that it is home in Kevin's hands now.

CindyL

[Raspy]

Cindy,

You have been treated very badly. They should never have charged you, or they should refund everything, since they were never able to make the repairs they charged you for. And to tell you it was done, when it wasn't is outrageous.

That company is completely unqualified to do the work. I hope you demand your money back, and give an appropriate review to help the next unsuspecting person.

[gordon2]

Originally Posted by Raspy

..
That company is completely unqualified to do the work. I hope you demand your money back, and give an appropriate review to help the next unsuspecting person.

Best option if you have time is to find a good shop, let them fix it, let them inspect the work done by the first shop and fix anything not done right, then ask the first shop to pay whatever the second shop charges you (under threat of lawsuit if they don't).

Originally Posted by CindyL

...Kevin is going to borrow the neighbor's jack, add ours, and buy another to see if he can fix it himself. ...

Be sure and use jack stands and not jacks alone.

[CindyL]

We will likely settle for a shitty (make that honest!) review. I suspect that as Kevin follows their repairs, he will be able to utilize what is there with minimal fixing. They did replace the 30 year old brakes and put in new wiring to those that I bet he can diagnose the issue, use what was put it, and make it right. I suspect that they did not connect it correctly.

I think that they know their boats, but are clueless on RVs. I expect that they are waiting for my review (Kevin was pleasant but firm and warned them that he was intermediary to a very-pissed off wife ). They respond each time a negative one appears. I wonder who they will blame, us or a 30 year old camper?

They need to fire their electrician along with the other guy who was fired.

CindyL

[CindyL]

Originally Posted by gordon2

Best option if you have time is to find a good shop, let them fix it, let them inspect the work done by the first shop and fix anything not done right, then ask the first shop to pay whatever the second shop charges you (under threat of lawsuit if they don't).



Be sure and use jack stands and not jacks alone.

He will be sure to be safe. Thanks.

[Joe Romas]

One thing on these replies that bothers me is people are referring to the "GROUND".
The brakes should be attached to the NEGATIVE wire that is commonly white in an RV. The wire size in the 7 pin pigtail for the brakes has a blue larger gauge wire, mine is 12 ga, than wires for signal and running lights that are commonly 14 ga. Yes I know the negative and ground leads are most likely connected somewhere in the trailer but the chassis ground should not be used for the negative battery lead

At 75 years old and a retired service technician I relearned last week what Gordon2 wrote above. I'm getting too old to craw around under a jeep but it's seems to be a necessary evil.

Cindy, you have much more patience then I and I hope your lawyer comes down on this facility hard\ Are you eventually going tell us who it is? I have a strong suspection who it is