electric brake wiring size
Submitted: Thursday, Dec 16, 2010 at 13:29
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83094
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Member - bungarra (WA)
I am about to fit an electric brake controller (Hayman Reese) to the Landcruiser. Upon examination of the vehicle wiring harness (factory fitted) there is the blue wire already connected to the correct pin at the trailer plug.
However it is the typical thin guage wire that comes complete in the 7 core flex........where the other end is connected to I have no idea as I havent looked....not really relevant anyway
Instructions with the controller do not suggest the wire size from the controller to the trailer plug nor does it give an expected amp draw for the electric brakes........I am assuming that the existing trailer wiring harness is too smaller a dia and that thereforeI will be running a dedicated blue wire for the controller to the trailer plug (and severing the existing one)
BUT can anyone tell me the expected amp draw of the brakes on the caravan and therefore allow me to do the job with the correct size cable?
Thanks
Reply By: Batt's - Thursday, Dec 16, 2010 at 14:44
Thursday, Dec 16, 2010 at 14:44
when I worked at TJM we ran a seperate 4mm wire to the trailer plug and soldiered it to brake controler wire and discarded the origional wire in the trailer plug don't forget to use a circuit breaker not a fuse.
AnswerID:
439051
Follow Up By: Batt's - Thursday, Dec 16, 2010 at 14:49
Thursday, Dec 16, 2010 at 14:49
ps.. check what angle you mount the brake controler at some brands are not to be mounted at great angles according to manufactures specs
FollowupID:
710886
Reply By: Roughasguts - Thursday, Dec 16, 2010 at 15:02
Thursday, Dec 16, 2010 at 15:02
I used as recomended by the fitting instructions a 20 Amp auto resetable circuit breaker about 10 bucks from just about anywhere.
So with that in mind 20 plus Amps should be around the expected max draw.
I used 6mm wire.
Cheers.
AnswerID:
439054
Reply By: Member - Graham H (QLD) - Thursday, Dec 16, 2010 at 15:16
Thursday, Dec 16, 2010 at 15:16
I have used twocore 6mm wire wound together at each end from the controller to the rear plug on a tandem setup Manages to lock up brakes with a Prodigy.
The Hayman Reece is a copy of the Voyager ???? which wasnt known as the best thing to have.
If you havent bought it yet buy a Prodigy or a P3 that you can mount under the dash on an angle and it works perfectly
AnswerID:
439057
Reply By: Shaker - Thursday, Dec 16, 2010 at 15:51
Thursday, Dec 16, 2010 at 15:51
You may find that the blue wire in the factory harness, isn't run allt he way forward, it is most likely sitting close to the left hand tail light as it is in the Prado. So all you do is run a reasonable size wire to join to it, the short run from there to the plug won't matter at all.
I spoke to Redarc about wire sizes & they didn't seem to think any more than 4mm was required for any of the wires, although I did run a 6mm to join to the blue wire in the harness.
AnswerID:
439063
Reply By: PradoMad - Thursday, Dec 16, 2010 at 18:24
Thursday, Dec 16, 2010 at 18:24
I had
mine installed by an auto electrician even though I'm pretty handy with that sort of things but did not wanna take any chances as it is a great safety feature.
Money worth spend and piece of mind
JS.
AnswerID:
439078
Reply By: Dennis Ellery - Thursday, Dec 16, 2010 at 19:54
Thursday, Dec 16, 2010 at 19:54
Hello Bungarra,
The draw on my caravan - dual axle – standard Alco electric brakes is 2.2 amps per wheel (4wheels = approx 9 amps at maximum braking stength).
My Haman Reese controller puts out 12 volts at max power and 3 volts at the min setting.
Hope that helps.
AnswerID:
439085
Reply By: Member - Stuart P (WA) - Thursday, Dec 16, 2010 at 20:31
Thursday, Dec 16, 2010 at 20:31
use 5mm twin , 5mm is the largest wire size that will fit the trailer plug, the other wire can be used to have power at pin 2 for trailer accesories
AnswerID:
439091
Follow Up By: paulnsw - Thursday, Dec 16, 2010 at 23:20
Thursday, Dec 16, 2010 at 23:20
5mm is what is required by law under ADR. Amazing how many car dealers that fit tow bars and auto electricians dont know.
FollowupID:
710954
Reply By: tasobb - Thursday, Dec 16, 2010 at 22:33
Thursday, Dec 16, 2010 at 22:33
dont forgett to run a bigger earth wire back to the vehicle chassis/earth as
well. not only does the power need to get to the brakes but back to the battery. as an auto sparky I have seen too many people fit big enough wire to the brakes, only for the earth to fail at the most inappropriate time,
AnswerID:
439110
Reply By: Member - Phil G (SA) - Thursday, Dec 16, 2010 at 23:59
Thursday, Dec 16, 2010 at 23:59
My trailer has 10" electric offroad brakes and I find in practice they draw anything up to 8amps (The max can be varied on my controller).
I used 12gauge tinned marine cable, which fits nicely into the large round 7 pin sockets and is capable of carrying 30-40amps.
AnswerID:
439114
Reply By: Member - Bucky - Friday, Dec 17, 2010 at 04:21
Friday, Dec 17, 2010 at 04:21
bungurra
As stated in a previous thread on this
forum, I used a minimum of 50 amp multicore wire, to the plug at the rear of my vehicle.
I want virtually no voltage drop.
Also from the plug to the brakes themselves I am sure that I used 30 amp multicore, again for the same reason, (no voltage drop).
Just trying to eliminate any problems
A heavy earth wire, was taken back to the same battery that powers the Prodigy.
Think I got it right !
Cheers
Bucky
AnswerID:
439120
Reply By: kcandco - Saturday, Dec 18, 2010 at 00:12
Saturday, Dec 18, 2010 at 00:12
Hi
I went to the Hayman Reese website and sent an email to them requesting fitting instructions. They emailed this to me the next day. Wire size on the instructions is minimum 3mm.
Kc
AnswerID:
439199