Electrical Jayco esc wiring

Matman699

New Member
Jan 13, 2022
3
0
1
Victoria
Hi there i just purchased a 2o15 jayco expanda.

I wired the 12 pin plug as per jayco wiring diagram. Installed a redarc tow pro elite.

Hooked the van up but when i apply the brakes it locks all 4 wheels with the slightest touch. I removed the 12v from pin 2 and the brakes work fine. Is there something i have done wrong to make the esc lock the brakes
 

Drover

Well-Known Member
Nov 7, 2013
11,410
17,863
113
QLD
www.expandasdownunder.com
Pin 2 is reverse lights, brake lights is Pin 6 and Brakes, as in electric brakes is Pin 5 ............. I would check that the pins wiring corresponds with the the standard 7 pin plug diagram ........... pick up 12v power for the tow pro direct from a fused battery source and the actuator signal from the brake light wire in the tow harness then you won't get a bad signal as most brake light switches are just a signal for the ECU so very low voltage and getting the signal from the tow harness doesn't give the ECU/BCM any drama...... Before doing that make sure your unit is dialled down though.

1642104978119.png
 

Drover

Well-Known Member
Nov 7, 2013
11,410
17,863
113
QLD
www.expandasdownunder.com
I would be doing a circuit test of the vans 7 pin to confirm the job of each wire, don't rely on colour...... ESC should be powered by a dedicated fused circuit using an anderson plug as the 7 pin really can't handle the current that may be demanded by the ESC, also the Breaksafe wiring needs to be checked as this can often cause drama if the wiring has been jumbled....

It does sound like the van plug is the culprit....unless you have got 2 and 5 mixed up on one plug.

Then check the tugs wiring, don't forget the earth circuits as well on both, manuals can be found online...
 

Boots in Action

Well-Known Member
Mar 13, 2017
1,670
1,409
113
Ferny Grove, Queensland
Hi drover thats how it is done although jayco say remove reverse wire and run 12v battery power to pin 2 for the esc
Hi @Matman699 , @Drover has sent you a picture of a flat 7 pin plug for your van instead of the 12 pin you have fitted. Generally speaking, his advices are correct. Pins 8 to 12 are not normally involved, but are intended to carry the heavier currents to the van - 35A as against 15A for the smaller pins. But for your info, this is what I have done for my van if you have a Setec BMS. If you are running your fridge, it must be connected to the heavier pins - # 8 hi current pos +ve from tug (Fused of course) and pin # 10 is the hi current neg -ve back to tug vehicle chassis. I have a separate dedicated line from tug to van with Anderson plug connections. Pin #2 was originally meant for reversing light from tug, but Jayco hi-jacked this connection to run 12 volt power to Setec (or similar) to charge van battery whilst on the move using pin # 2 on van socket (Aux input) . This meant that you had to terminate (or disconnect) this wire at the tug socket (thus disabling the reversing lights) and run a separate line from tug battery to pin # 2 connector to provide power to van battery via Setec. If you want to keep the use of your tug reversing lights, do not use pin #2 on tug and use a separate heavy line from tug battery to pin # 8 on tug socket and use pin # 8 on van plug to provide power through the Setec to charge van battery when moving. Pin # 10 then provides a heavy pin connection for the earth return to tug If you have all the wiring correct as @Drover said, then make sure you dial down the braking power so brakes are not locking up.
 

Matman699

New Member
Jan 13, 2022
3
0
1
Victoria
Hi everyone. Thanks for all of your advice. Looking into it a bit more today it seems more likely that it is the breakaway that is the problem. Everything on the car side is wired correctly but will have to look into van side as it seems when the brakes are applied it is activating the breakaway
 

Drover

Well-Known Member
Nov 7, 2013
11,410
17,863
113
QLD
www.expandasdownunder.com
The instructions for the Breakaway are easy enough to find online, if the van was wired up for NSW it will have a purple wire for the breakaway monitor in tug, as NSW required one to be fitted in tug, other states didn't, NSW doesn't require it anymore ....if this is in the van plug then disconnect it and your problem may be solved........ the Breakaway should have just a 12v supply from tug to charge its battery but it may be getting power from the 12v van supply loom elsewhere....... the blue wire is your brake wire so that should be the only one on the #5 pin ....... a meter on this pin should only be active when the brake pedal is pushed or the button on the controller, if it stays alive when neither are operated then you will have to find where the power is coming from by simple disconnect of any other live wires... (pull pin on breakaway will activate the blue as well)

Take Note that wiring found in caravans may vary between fittings, do not assume RED is POS (+ve) and BLACK is NEG (-ve) , sometimes White can be NEG( -ve ) with BLACK POS (+ve) , so it pays to check the polarity of connections when testing circuits ..... brown will come into the equation as well at times, mostly lights though. 7 pin plugs are pretty standard the 12 pin can throw the odd curly colour so always test to confirm voltage and polarity, some equipment will not handle reverse polarity at all, don't assume it was wired correctly in the first place, you can even find a mod may have been done further down the line out of sight, the fuses in the fuse board may not match their labels either, you pull a fuse and the circuit you are working on is still live, test always to be sure.....
 
  • Like
Reactions: Boots in Action