Anyone good with electric trailer brakes???

[prostreetC-10]

Hey guys....I have an 87 Circle J horse trailer with 4 corner trailer brakes and I can't get them to work. The guy I bought it from said they worked but the wire was bent back from the 7 pin connector and I'm suspect. It has the break away system that is supposed to have the 6V flashlight battery hooked up in the tack room but that didn't work when I hooked it up. I'm usually really good with electrical but am not really too sure where to start. Is there a common area to look at first or things to eliminate right off the bat? Should the brake be able to work with a car charger or do you need a battery to test? will they only work with a trailer control in the vehicle? Any links or tips would be great!!!!

[ChiefRocka]

I'm assuming you have a NICE, GOOD GROUND on the trailer.

Typically, a blue wire is used for the trailer brakes. Power from the truck plug flows from the truck to the brakes...in your case it is split into the four wheels. The backing plates have two wires...one should be GROUNDED and the other tied to the rest of the brakes to the wire mentioned above.

The break-away should be using a 12 VOLT battery. The battery is grounded, the positive goes to one wire of the break-away switch, the other wire ties into the same wire mentioned above (feeding the brakes).

That battery should have a charge wire from the truck as well.

Now, you can use a battery charger to activate the brakes. However some chargers are designed to charge a battery, and won't supply a constant 12v source.

I use one that has a 'manual' switch with supplys constant power for test lights, brakes, etc.

It's pretty basic...just sounds like you have an 'open' some where.

Check the wires from plug to brakes. Pull back the plug cover, and check the wires in the plug itself.

When you step on the brakes in your truck you should have 3 to 4 pins hot (LT, RT, ELECTRIC BRAKES, and mabey CHARGE power).

Some trucks supply charge with 'key-on' only.

How this helps !

[prairewolf]

we bring all our work trailers in once a year for annual inspections, it is a Horse Trailer Sales place, .... they fix anything wrong, ... maybe have someone like that fix yours,...... it might be money well spent and not that expensive.... get a quote from them first if you want it.

just a thought.

kent

[Richard H.]

What Chief sez and R V online sites are a good source for diagrams.
Something else is I think there is a difference in vehicle harnesses ,ie; furd vs Chevy and an RV joint sells a crossover adapter.

[fastwillie 696969]

all you need is a volt meter from radio shaq for 10 bucks ,