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SafariFaye · 03-17-2012, 06:08 PM

Faye is a '64 Safari. Like most women in my life, I love her...but she confuses me and makes me angry at times.

While removing the old axle today, I ripped out the wiring for the brakes from under the belly pan. I'm holding a 10' piece of wire that has a yellow and a white wire (that connected to the 2 wires on the old brake system).

Under the belly pan, I can see 1 long yellow wire that is connected to the bundle of wires running to the back of the trailer on the curb side. I don't see anything for the white wire to be connected to.

It appears that the yellow wire from the "bundle" was connected to the 2 yellow wires that connected to the brakes (split with a wire nut for 1 wire to connect on each side of the axle) and the two white wires were simply connected together. White is listed as "ground" on the diagram.

Here is my question/thought... is the axle "ground" enough for this to work? It appears that is how it was before my brain "cramp". The brakes on the old axle worked fine. I would think the white wire should have a "ground" to the frame, but I can't find one. Trust me, what the PO did to the wiring it wouldn't surprise me.

I'd attach a pic of the situation, but I could barely get under there to fix the wiring.

Help

!!!

Jason

idroba · 03-17-2012, 06:25 PM

Your yellow wires are the "hot" ones that go to the brake controller via the TV cord/plug/socket arrangement. The white wires should be connected to the main white ground wire, somewhere up near the front of the trailer. That white ground will also be the point for the white ground (-) wire from the TV bundle.

Yes, you need a very good (-) or ground connection for the brakes to work properly.

And yes what PO's did can be nutsy. You can't blame that on Faye. She may have been a victim.

idroba · 03-17-2012, 06:28 PM

Oh, don't forget the yellow wire will also need a connection to the break away switch on the trailer tongue. The other side of that switch will need 12 volts from the AS battery. Usually that is the same as the charge wire from the TV, and the one which goes to the power jack if you have one of those.

SafariFaye · 03-17-2012, 08:25 PM

How do I check to see if the setup is correct? Just hook up our TV and check the +/- with a volt meter?

idroba · 03-17-2012, 09:12 PM

The brakes don't care about polarity, just have + to the one wire (yellow on the original) and - connection to ground on the other wire for both wheels. Well, if the new magnets have a color difference on the wires, probably it would be white (the ground or - side) and black ( the + side). But if they are the same color either wire will do for + or -.

The best way to check things is to put an ammeter between the + wire (you have been using yellow) and a 12 volt source. Most brake magnets take 3 to 3.5 amps, so a pair should take 6 to 7 amps if all the wiring is correct. Or, trust Faye and hook her up and tow, hit the brakes with the manual control and see if you can lock them up on gravel.

Jammer · 03-17-2012, 10:44 PM

Hi Jason

It is not unusual to run into dodgy brake wiring.

The right way to do things is to run a "wired ground," that is, a ground wire extending from the brakes all the way up to the umbilical connector (the connector to the tow vehicle), rather than rely on the frame of the trailer. While the trailer frame will generally provide a good ground the axles may not be electrically connected to the rest of the frame, and there is no means of connecting a ground wire to the steel frame that will perform reliably for many years in the presence of road spray.

The "wired ground" method is being used by Airstream for new production trailers and has been for many years.

You may decide to use the frame ground anyway. If you do, ground to the frame, not the axle, and use emery cloth or sandpaper or a file or wire brush or whatever to get the steel clean and bright. Connect using a bolt, nut, and internal tooth star washer, and use anticorrosive electrical grease on everything. The stuff they sell in the home stores for use with aluminum wire will work OK, even though you're using copper wires.

Wire nuts should not be used because they will come loose from vibration. Either solder the wires or use crimp connectors with a good crimp tool.

slowmover · 03-18-2012, 06:06 AM

I agree with the wired ground approach. Brakes should take a very good deal of your time and thinking to make as good as is possible (better than what you may consider "possible" based on current skill level). Time and a plan work best:

RV.Net Open Roads Forum: Towing: Independent Brake Wire Feed Upgrade

SafariFaye · 03-18-2012, 03:58 PM

Thanks for the help! Everything is back together and functioning. Next time I'm under there, I'll be checking the ground connection. Getting it back to the umbilical connector isn't an option without some serious belly pan manipulation, so I'll triple check my ground. Thanks to REDNAX for some really good ideas for a future project. Thanks to idroba for confirming my hunch on the +/- stuff. I'm coming from an automotive background, so I'm more comfy with 12V. I'll be asking more questions when we decide to change out our "Soviet-Surplus" looking converter unit.

Thanks again, what a great (and helpful) group of people. Someday I hope to return the favor.

SafariFaye · 05-06-2012, 07:21 PM

SUCCESS!!! Fixed the brakes today. Just needed to make a small access hole near the connection of the break wires and the umbilical wiring that runs down the curb-side of the AS.

Connected the yellow brake wire to the "hot" wires to the new brakes and re-connected the ground that had been torn off in the axle repair.

Thanks to all who helped. I hope to return the favor some day!