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VT - wiring electric brake controller, locating a direct + / - cable to splice into?

sjl81

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Hi all,

I am about to wire up a tekonsha primus iq brake controller to my VT wagon. I've got the brake feed / stop light wiring sorted, am going to run wires from the trailer plug to the dash area. The instructions say to wire the other 2 to a the positive terminal and to ground. It states in the absence of a "trailer tow package" ground to the negative terminal of the battery.

So, does "trailer tow package" in any way refer to the trailer plug at the rear, in other words can i run this earth cable from the trailer plug back to the brake controller?

What would be my best way of connecting to the positive terminal of the battery? are the any wires/harnesses I can splice into in the dash area?

I need to fit a 20A circuit breaker on this positive cable, too, it is metal, has no istructions, but am wondering if it needs connecting to the body of the car for earthing?
 

rambunctious

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I don't know if it is different to the Tekonshea units I've used over the years but the following applied to all of mine.

Brake wire to unit comes from brake switch at top of brake pedal.
Earth wire to unit from any good earth point under dash or side panel etc
Main power straight from positive battery terminal with circuit breaker screwed to inner guard etc as close to battery as possible and it needs to be heavy wire, not sure of amperage but probably 30 amp seeing as you have a 20 amp circuit breaker.
Also the lead from the unit to the rear plug needs to be at least 15 amp I believe but not sure.

I googled this

DIY - Installing an Electric Brake Controller
 

axemurderer101

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This is how i do these at work ( auto electrician ive done heaps lol)

Run some 5mm twin through a grommit in the firewall to the brake controller with the red wire through the circuit breaker at the battery, then the red wire goes to the black wire from the brake controller.
The black wire form the twin can be used as an earth for the brake controller (white wire) then just connect the black wire to the negative post of the battery.
If you are towing a caravan the black wire would go through a fuse holder on the positive post on the battery then you would just earth the white wire of the controller to an earth bolt under the dash instead . this black wire will be used to run the fridge and trickle charge the battery in the caravan.

Next you run another length of 5mm twin from the dash area to the trailer plug, the black wire we run into pin 5 for the electic brakes and the red wire would go to pin 2 if you are towing a caravan. Its also best to run a single 5mm wire from pin 3 to a good body earth bolt. Then back at the controller you join the black wire of the twin to the blue wire from the controller and join the red wire to the black wire from the other twin if you wired up the fuse holder.

Kinda hard trying to explain it to someone who hasnt done it before lol
 
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