URGENT no caravan brake light output

[Pittsy87]

Hi All

Got van going to vicroads for a transfer and inspection tomorrow morning and now there is no power on my brake light wire at my trailer plug (car end)
Also my redarc towpro elite is flashing green constantly and not applying trailer brakes when you push the brake pedal. (Unsure if this is related to no power on tralier brake light wire???)
My car brake lights are still working fine and the override button still applies power to electric brakes on van but not working via brake pedal.
Any help would be extremely helpful or i will have to cancel inspection in the morning if i cant get it to work tonight.

[nj swb]

Do any of the lights (indicators / tail light) work on the caravan?

[spot01]

Do the car's hazard lights work - if not, check fuse & fusible link - there is a thread about this common issue.

[Muzza]

[QUOTE=Pittsy87;615836]Hi All


My car brake lights are still working fine and the override button still applies power to electric brakes on van but not working via brake pedal.
/QUOTE]

I would suggest to check the wire from the brake pedal to the red arc unit, as it sounds like it ain’t getting a brake signal.

[nj swb]

If you have a genuine MM bar you probably have the genuine MM trailer harness, which I believe includes a separate ECU to "relay" signals to the trailer, rather than piggy-back off the existing circuits. If this ECU loses power, no trailer lights will work.

Can you confirm all other trailer lights work?

Also my redarc towpro elite is flashing green constantly and not applying trailer brakes when you push the brake pedal.

Have you checked the Redarc manual?

I can't get to Redarc's website (seems to be down) but I found a PDF of the manual: https://www.manualslib.com/manual/13...page=19#manual

If the LED is flashing green, it may be because the Redarc didn't start up properly. The suggested fix is to disconnect the black wire from the battery, wait 1 minute, then reconnect.

[Pittsy87]

Hi guys.
Yes all other lights and hazards are working perfectly on paj and van, its only the brake signal not arriving at the paj trailer socket.

And in regards to the electeic brakes i have tried the above mentioned what the book says about disconnecting power for at least one minute and reconnecting and still no good.

Looks like its an issue with the paj wiring somewhere all of a sudden or its canbus coz i just hooked up van to the old mans 80 series and everything works fine including his old school red arc brakes.

I do have the factory mm trailer loom and i also purchased the factory mm electric brake loom to go with the red arc brake module thinking this would be the best way to do it using as much mm factory supplied looms but something aint right.

The weird part is when i picked the van up from tassie a few weeks back everyrhing worked when i tested it on the van at the car yard.
Strange......
Looks like its a job for an auto elec one day soon.

Thanks for your responses!!

[spot01]

Have you checked the wires inside the back of the trailer socket on the Paj? Unsure if this base is open or sealed, but over the years I've found a few either with a loose wire or so much crap inside that contact is lost. Make sure all light switches are off & be careful not to short anything out if you have a power feed in there.


Re the ECU for the trailer wiring - it lives inside the trim inside the back door. You can hear the relays clicking each time a light is activated from the car. You can hear it yourself if there is no other noise around & your hearing is good, or get someone to push the brake pedal whilst your listen inside the back door opening. Try indicators & other lights to hear what it sounds like, then listen for the brake click. (I just checked this in my car & I can hear the clicks)

[Pittsy87]

Yes mate.
Checked paj 12 pin trailer socket wiring and also van 12 pin plug and everything was fine.
I only swapped my 7 pin to a 12 pin 2 weeks ago so wouldnt have thought anything was wrong with it, which there wasnt.

Will have to listen out for relays in the back door like you said
Do they only activate when the trailer is connected or always when the brake is pressed or indicators used etc

[spot01]

Yes mate.
Checked paj 12 pin trailer socket wiring and also van 12 pin plug and everything was fine.
I only swapped my 7 pin to a 12 pin 2 weeks ago so wouldnt have thought anything was wrong with it, which there wasnt.

Will have to listen out for relays in the back door like you said
Do they only activate when the trailer is connected or always when the brake is pressed or indicators used etc

They make clicks without a trailer connected. Parking lights are easiest to hear as indicator clicks from the dash may confuse.
Did the trailer brake lights work after you changed the pins?

[Morville]

Can I suggest applying 12v to the red wire at the back of the redarc unit (wire from brake pedal). If it now works this will indicate if the wiring or brake pedal switch is faulty.
Peter

[Garc]

I had exactly this problem last week. Did all that you have done. Found it was the connection on the positive battery terminal. The terminal had some corrosion - cleaned it, put a better washer on and now have a coating on it.

[Mike DiD]

If you're using the Mitsu wiring harness, the ECU is above the right rear wheel arch - just pull out the plastic trim around the third row window and you can reach down to it. There is no trailer wiring inside the rear door.

There is a fuse INSIDE the wiring harness that connects to the Brake Pedal Switch - this has been to blow.

[deekay]

I have had this same problem & fixed it by getting a small screw driver and opening the space a fraction in the pins in the trailer plug so that they made good contact when plugged into the socket on the car.