Dexter brake actuater question.

[Ironwood]

Well, I need some help. I am working on trailer wiring and need to know if there is a polarity concern when wiring up the axles. I seem to be getting "feedback" from the axles. The normally positive wire that engages the brakes when plugged in is giving me a "ground" when not hooked to the truck. IS this normal, much like receiving negetive feedback thru the filament of the light bulb? For instance when checking for a short in the lights you would need to unplug all the bulbs so as not to get feedback thru the filament (a false ground). Could this same thing happen thru the brake actuators behind the brake drums, as they are sort of coils?  Or when a actuator is shot how does it behave? The brakes all actuate and seem to function fine, at least individually. PLEASE HELPPPPPPPP.

                     Thanks Reid (out in the rain, trying to figure it out)

[Ironwood]

Well, no polarity according to Dexter. I can't figure out why I am getting a ground reading from the supposed hot wire. I did just put new shoes all the way around. I tried indivdually checking to see if a wire was pinched on each axle by electrical tester. I guess tomorrow I pull each brake hub and bearings, but if they work it shouldn't be pinched!!! >:(. I am gettiing grumpy). 

               Reid

[Captain]

Unpowered, if measuring with a volt meter, you'll measure ground.  The wonders of electricity.  The trick is to measure the resistance to ground, that will tell you if the part is correct or not, at least statically.  Check its resistance VS another actuator.

Captain

[Ironwood]

Captain,

THANKS, I been chasing gremlins today, in the rain. I finally just tarped the trailer and lifted it up to create my own dry easy to reach work space. The beauty of two fork lifts (I my wife wonder why I need two :D). Thanks again. Reid

[Gary_C]

Reid
Those electric brakes sure can be frustrating.

You should have some resistance between the two coil wires, like 5-10 ohms, that is due to the windings in the coil. However you should not have any resistance between either wire and the trailer ground. To test that you must disconnect the trailer ground from the two wires that run to the brakes.

I have found that it is best to run a pair of wires all the way from the front of the trailer to each brake.  That way you only make one ground connection at the junction of all the wires. Do not rely on the frame for the brake ground connection and do not allow either wire to be grounded other than at the front. That way there is no chance of crossing the hot to ground. Plus, if you have a problem with one wire, it only affects one wheel unless you ground the hot wire.

[Ironwood]

Running the full distance is also Dexter's recommendation, and this is how mine is wired.  Thanks Reid

[Quartlow]

I would go one step further. I run my ground straight from the battery. That way theres just about no way to lose ground. We wired the semis this way all the time. Nothing worse than hooking to a trailer and having to figure out why the lights won't work on a cold winter night

[johnjbc]

Does the wiring go through your axels. I had a problem like that and it turned out that the insulation  had worn through inside the axel where you couldn't see it. And when you hit a bump it would short out to the inside of the axel.
Believe me it makes for a fun ride down the mountain when the breaks quit.
:

[Ironwood]

Checked the axle tube wire run and they were fine. Goood idea though. Thanks, Reid

[Ironwood]

WELLLLL, reluctant to admit it but I had the @#$$#% plug 180 degrees out. I read the schematic facing the back of the plug not to the front. The BASICS will get you everytime. Wasted untold hours figuring this one out, Oh well at least is fixed and the trailer has ALL new wiring :D  Thaks for all the suggestions. Reid

[pineywoods]

Hey Reid, don't feel bad, I've done the same thing TWICE. One took out a bunch of fuses on my motorhome