On Thu, 16 Aug 2012 21:10:06 -0700, Larry Jaques
wrote:

On Thu, 16 Aug 2012 23:34:38 -0400, wrote:

On Thu, 16 Aug 2012 07:03:50 -0700, Larry Jaques
wrote:

On Thu, 16 Aug 2012 17:25:37 +1000, John G
wrote:

John B. formulated on Thursday :
On Wed, 15 Aug 2012 19:38:19 -0400, wrote:

On Tue, 14 Aug 2012 20:27:20 -0700, "Steve B"
wrote:


"Richard" wrote



If it's more than a single axle, remember, they are to be wired in
parallel, not series.

A battery and controller sitting by the wheel might help.

Wire it up and squeeze the tit.
See it the brake moves.

Check them all, If they all work, back track through the wiring to the
connector.

DON'T use the trailer frame for ground!

And a circuit tester with a light works better than volt meter.

Thanks for the tips. I woulda got the ground thing wrong.

Steve

Commercial trailers have been using the frame for ground for decades -
and it works if it is done PROPERLY. Harder to screw up a fround WIRE
than a frame, but also easier to damage the WIRE. Six of one, half
dozen of the other, in my books. I'll stick with a "chassis ground" -
same as used on the tow vehicle, and same as has been used for
decades.

Don't most automobiles uses a "frame ground" :-)
Cheers,
John B.

No.

Correct. And I recreated all sorts of wiring looms for autos for which
no harness was available back when I worked at the body shop.

Only the Brits, using "Lucas, Prince of Darkness" technology, use body
and frame grounds. Ask any Brit car owner how he likes it.
But be prepared to run. Some are _really_ fired up about it.
I beg to differ with you. Body grounds were very common on every
American,Japanese, or German car I ever worked on as a professional
mechanic , and my current vehicles (OK, they are 10 years old) still
use chassis/body grounds for the majority of the circuits. Tearing the
wiring harness out of a friend's Miata, there were numerous "ground
points" where the black ground wires were screwed to the body/chassis
and a friend's F150 also used body grounds extensively - and one that
was connected to a patch of ferric oxide caused considerable problems
untill it was located (and the windsheild fixed to prevent more
rusting)

Perhaps this came about since '85, when I retired from wrenching? I
don't recall seeing too many frame grounds and NO body grounds except
for a few on the firewalls, which mostly connected harness grounds
together.

But the Brits grounded each lamp/motor at the site, creating a
nightmare for the owners because the fenders/bonnets/doors developed
rust between parts and the oxidized contacts didn't permit proper
electrical flow. Watching a Brit car on a back road at night, you'd
think they were a Morse code billboard. blink, blink, b, b, blink
I've been wrenching since 1968, and on just about any make you can
name - and ALL of them used a chassis return ground for MOST of the
circuits. Yes, on many makes there were a cluster of wires brought out
to one ground point where they screwed to the body - but even many
American vehicles grounded the tail lights - for instance, by bolting
them to the body, and the bulb socket grounded to the pot-metal lamp
housing. OK until it turned to dust. Or to the cadmium plated steel
lamp housing. Which sometimes rusted out. Or the socket rusted out.

But just about as many power wires corroded off at the socket, or
inside the harness - particularly where wires were joined together in
the harness, way back in the taped-up mess of wires. A whole lot
EASIER to find and repair a bad chassis ground than a bad wiring
harness - and you can take THAT to the bank!!!!