stupid breakaway cable wiring...

[woodtrucker]

I have been perplexed which is easy to do since I'm not an electrician but try to do things safely.
I have wired up the breakaway switch as the diagram here suggests.
I have crimped a ring terminal onto the black wire and attached it to the + pos battery. I've spliced in the blue cable from the breakawy switch exactly where the old switch was spliced which is coming off the brake signal from 7way plug which is a blue wire.
I hooked everything up but the 7way and pulled the pin and no breaks.
Just to check to see if the switch was good, I disconnected the brake (blue wire from break away switch) and measured voltage across that wire and ground stud on camper. 0 volts when pin is in switch and about 11 volts when pin is pulled. Seems right but does that voltage need to be higher? Hooked everything back up and tried it with cable attached in the brake (blue) wire and no brake hum at all. Funny thing is, the brake work fine from TV so I know everything is hooked up correctly on brake wiring...any suggestions?

[woodtrucker]

by the way,
thanks to EVERYONE for being so helpful, polite, and knowledgeable.
This is by far the best forum I've ever been part of!
:B

[woodtrucker]

thanks bartlettj,
I ended up jacking one side of trailer up. pulling pin and check wheels. No issues.
Brakes were locked up tight so I'm ready to hit the road again.
I checked all my connections, plugged camper to shore power and checked the charge on battery, check 7 way plug on TV and all seems to be working and powered. Problems solved and ready to hit another state park in a few weeks!

[bartlettj]

The brakes don't hum with the breakaway switch in use. You should hear a click, and you should be able to rock the trailer slightly and then the brake shoes should lock up as the rolling action of the drum against the magnet wedges them into the tight position. The hum is from the brake controller modulating the voltage to the brake magnets.

[woodtrucker]

I just jumpered a wire over from positive terminal to brake wire in camper to see if I could get brakes to actuate by touching it to the positive battery terminal and I get a weak clicking sound but then when I plug in TV and push override down all the way I get a good hum on brakes. I left the camper plugged in over night and the battery was charging at about 13.6 volts. When I checked the switch this morning (before this last test) I measured voltage accross battery with breakaway switch pin in place and got 12.6 volts and with it pulled I got 12.4 volts so it is drawing on the battery so is it safe to assume that it's working even though I really don't hear a hum?

[69_Avion]

I would try charging the battery and then see what happens. The output of the switch goes right to the brake wire which is usually blue in a standard wiring diagram. As far as putting a fuse in the break away switch line, if I was going to do any type of current safety it would be an automatic circuit braker. The last thing you want to have happen is your trailer not stopping if it becomes disconnected from the TV.

[RCMAN46]

If you measured 11 volts at no load on the battery then I am almost sure the battery is toast. If it has been at 11 volts very long it most likely will not take a charge.

[Sea_scape]

If I read your first post correctly, you measured 11 volts from the break switch to ground. This is without load because you had disconnected the blue wire to the brakes. This is an unchanged battery, and the voltage will drop more when the brakes are connected.

Charge the battery, or plug the trailer in to see what happens. Measure the voltage as you did, but with brakes connected and you will see actual voltage.

[woodtrucker]

I did get a new battery from walmart and have not had it hooked to shore power since carrying it off the shelf. I guess it's possible that 10-11volts is just not enough to energize the brakes. I'll charge it and see if that helps.
Thanks,
Scott

[Puttin]

Here is a bit more:

Trailer Wiring

[weasel4]

woodtrucker

Make sure the battery on the towed vehicle is up to snuff, for a charge.
BTC

[Sea_scape]

One difference is when plugged in you are using the vehicle battery;when not plugged in you are using the trailer battery. Measure the voltage the way you did, except with the wire connected to the breaks. If the trailer battery is weak, the voltage might be pulled to low.

Also check the ground wires. They are often notorious for giving false readings. I am always cautious about open circuit measurements because of possible back feeds.

You can also try connecting a wire directly from the battery to the one you believe energizes the break. If the brakes work the problem is in the brake switch;if they don't work, the problem is in the wiring to the brake. You may even be fooled by which wire the brake is, but not likely if you connected the switch where the old one is.

Problem solve to isolate the area not working.

Good luck.

[powderman426]

You should also put a fuse on the wire from the battery that is fused for the gauge of wire from the battery. Also you should have a higher voltage than that if the battery is fully charged though that wasn't low enough to keep it from working.

[downtheroad]

You connected one line to the positive battery...that is correct...

You said you wired the second line to the brake signal..I thought it was suppose to be wired directly to the trailer brake line...