Why is this emergency breakaway switch not working?

grumpyer · 03-18-2015, 11:22 AM

While I'm replacing tires today & since it's jacked up I decided to check the breakaway. pulled the pin but brakes did not lock up drums spin?????

Yes I have 12v to it!
What is your experience with this?

OldCoot · 03-18-2015, 11:25 AM

Quote:

Originally Posted by grumpyer

While I'm replacing tires today & since it's jacked up I decided to check the breakaway. pulled the pin but brakes did not lock up drums spin?????

Yes I have 12v to it!
What is your experience with this?

Did you spin the drums while the pin was pulled? The drums have to turn to engage the magnets and the magnets grab the mechanism and engage the shoes. Usually take about 1/8-1/4 turn.

geotex1 · 03-18-2015, 11:25 AM

Well, if you have +12VDC at the magnet, do you have ground?

**wmtire** · 03-18-2015, 11:29 AM

Quote:

Originally Posted by grumpyer

While I'm replacing tires today & since it's jacked up I decided to check the breakaway. pulled the pin but brakes did not lock up drums spin?????

Yes I have 12v to it!
What is your experience with this?

Just to be sure, when you say you have 12V to it, do you mean from your trailers battery or from your vehicle?

The breakaway is wired to pull power from the trailers battery (which is the only way it can get power if it breaks away from the tow vehicle). If for some reason, you have the trailers battery disconnected or removed, then the breakaway will not work.

grumpyer · 03-18-2015, 11:32 AM

OldCoot, I spun drums

geotex, I assume wiring is all intact everything else works! May hve to trace wiring back to brakes huh?

grumpyer · 03-18-2015, 11:33 AM

Quote:

Originally Posted by wmtire

Just to be sure, when you say you have 12V to it, do you mean from your trailers battery or from your vehicle?

The breakaway is wired to pull power from the trailers battery (which is the only way it can get power if it breaks away from the tow vehicle). If for some reason, you have the trailers battery disconnected or removed, then the breakaway will not work.

trailer battery

**wmtire** · 03-18-2015, 11:36 AM

Quote:

Originally Posted by grumpyer

trailer battery

If the trailer brakes work when hooked to the tow vehicle, I would suggest starting at the breakaway switch itself, and trace from there.

geotex1 · 03-18-2015, 11:38 AM

Quote:

Originally Posted by grumpyer

OldCoot, I spun drums

geotex, I assume wiring is all intact everything else works! May hve to trace wiring back to brakes huh?

Test at brakes first, then work back against what you don't have there. Just because everything above deck works doesn't mean the ground point for the brakes is good for instance. I've had breakaway switches actually fail with a piece of the pin in them and not trip.

grumpyer · 03-18-2015, 11:41 AM

Ok...looks like wiring only goes to left side I have right side jacked up right now. I'll post back once I get to that side.

geotex1 · 03-18-2015, 11:44 AM

Quote:

Originally Posted by grumpyer

Ok...looks like wiring only goes to left side I have right side jacked up right now. I'll post back once I get to that side.

Wiring to that side should be on the axle tube with some version of crimp connector behind the backing plate. Test there.

grumpyer · 03-18-2015, 04:51 PM

Alright, I'm back.
After getting left side jacked up I saw where wires are ran to right side.
with pin pulled still don't lock up. I have contact in switch. power to switch is good. Blue wire coming from switch which I assume provides 12v to brakes I have no power.

Bad switch? What do you guys think. I wish I were an electrical engineer!!!!!!!!!!!

geotex1 · 03-18-2015, 05:02 PM

Quote:

Originally Posted by grumpyer

Alright, I'm back.
After getting left side jacked up I saw where wires are ran to right side.
with pin pulled still don't lock up. I have contact in switch. power to switch is good. Blue wire coming from switch which I assume provides 12v to brakes I have no power.

Bad switch? What do you guys think. I wish I were an electrical engineer!!!!!!!!!!!

You found it! Bad switch. This is why I tell folks to test their switch regularly, but only when disconnected from the TV!

grumpyer · 03-18-2015, 05:25 PM

So if I jump the blue wire running back, to 12v they should engage, right?

Maxhise · 03-18-2015, 05:32 PM

Slightly on topic. I learned this one the hard way.

I was parked on pretty good incline last summer. Nothing extreme but I was a little uncomfortable with the slop. I used X chocks and blocked the tires. Then I decided for an extra security measure, to pull the pin on the break away brakes.

This is a 'no-no'. Turns out the brakes draw more juice than the charger provides. After about 2 or 3 days I noticed the fridge and lights etc... wouldn't work without the generator running. I assumed the battery was shot so I replaced it. After a few more days, it started doing the same thing. When it came time to leave, I couldn't move the slides or the landing gear. Since it was already dark, I decided to stay an extra night and mess with it in the day light.

About 2 am, it hit me that it could be the brakes so I got up and put the pin back in. When I got up in the morning, everything worked great.

Lesson learned and all it cost me was $140 for a battery and about $50 extra worth of gas because I had to run the generator 24/7.

geotex1 · 03-18-2015, 05:33 PM

Quote:

Originally Posted by grumpyer

So if I jump the blue wire running back, to 12v they should engage, right?

Correct. Be sure to jump with an appropriate gauge of wire and not your tester. Magnets draw some amps!

**Flybob** · 03-18-2015, 05:35 PM

I use a small shoestring size bungee cord to attach the breakaway cable to the top of the tongue jack when I am hooking up/unhooking as a backup in case the chocks fail, I can pull it and stop the trailer.

grumpyer · 03-18-2015, 05:37 PM

Quote:

Originally Posted by geotex1

Correct. Be sure to jump with an appropriate gauge of wire and not your tester. Magnets draw some amps!

Thanks for the help!!!

grumpyer · 03-18-2015, 05:40 PM

Quote:

Originally Posted by Flybob

I use a small shoestring size bungee cord to attach the breakaway cable to the top of the tongue jack when I am hooking up/unhooking as a backup in case the chocks fail, I can pull it and stop the trailer.

That is a great idea...yet so simple I would have never thought of it!

Det107 · 03-19-2015, 12:08 PM

While replacing my brakes on our 5th wheel the mechanic said when you test your breakaway switch you shouldn't leave the pin out very long because they can burn out within minutes.

NCBBA11043 · 03-19-2015, 01:53 PM

Quote:

Originally Posted by Maxhise

I was parked on pretty good incline last summer. Nothing extreme but I was a little uncomfortable with the slop. I used X chocks and blocked the tires. Then I decided for an extra security measure, to pull the pin on the break away brakes.

Don't EVER do that. You will burn out the electromagnets. They are not rated or meant to be "hot" for extended periods of time.

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