Electrical No Brakes on the Panda

[Holden_man]

Hi Folks,
Thought I would share a recent experience regarding a brake problem on the Panda.
Hooked up the panda for the Easter school Hols and pointed the Prado for South West Rocks, in NSW at 6am Easter Friday trying to beat the traffic.
We have a Tekonsha P3 Brake controller pulling in the brakes on our 18' Panda.
I still class myself as a bit of a caravanning novice had the Panda for 2 years but am always learning.
When ever I pull the Panda out of the yard we check lights and I activate the manual braking on the P3 to make sure it she pulls on the Prado, then away we go. This time I forgot to check brakes but while trundling down to the end of our street I definitely found it hard to pull her up and felt the Panda trying to push me across the intersection. As I was only doing about 30km everything pulled up ok though with a bit of effort. I noticed that the P3 wasn't outputting any Voltage to the Brakes, it just read 0 when applying brakes, Around the corner at very slow speed I activated the manual braking (as I should have out the front of the house) the Panda pulls on the Prado for a second or two and the P3 powers off. Yep it actually dies. So not only was the P3 not outputting voltage/current but it is now dead.
I pulled over around the corner about 5km from home, with the early start to beat the Easter traffic finished with.
Checked the main fuse for the Brake controller and found it blown. Stuck another 25A fuse in, everything powered up, as soon as I activated the main brake it pops. Time to pull the Panda the 5km home without brakes and regroup.
Got home and started by pulling both trailer and vehicle plugs apart. Found them full of Red Mud. Been plenty of rain in Brisbane, and with the recent trip to Cameron corner filling the plugs with dust this had now turned into Mud. Cleaned this out and the main fuse holds.

Started working on the lack of output voltage. Normally when stationary the P3 outputs a holding voltage, but when I put my foot on the Brake it was reading 0v.
Started tracing cables and looked up the wiring connection drawing and found the following.

The P3 has a helpful diagnostic menu which shows the common voltages and output current. It also shows the Brake input Voltage, without this signal, the Controller doesn't know you are braking. Its only with this signal the P3 will apply proportional output voltage to the brakes.
My display looked like this with Brakes applied, should be 12v


I found the other end, it was wired in the vehicle trailer plug by the Auto Elec and was connected to the Pin for the Brake lights to the van. The pin had 2 wires, the Brake light signal from the Prado to the Panda, and the wire back to the P3 to give it 12v for the Brakes Activated signal. With Brakes applied I had 12v at the trailer plug but not at the controller, now looking for a broken wire. or dodgy join by the auto elec.
Climbed under the Car and there it was, a single broken core just back from the Trailer plug on the Prado.
Looks like on the Trip to the Corner a rock has hit the Prado's trailer wiring loom and cut the Brake wire to the controller. The wiring Loom was very poorly protected, just really loose cables, dodgy Auto elec after all. Joined the Cable and hey presto the brakes are back. 4.5hrs later we are back on the road, amongst the thousands of others getting away late for easter...

Now here's my take outs from this experience:
- Seal up the plugs on the trailer and vehicle to try and keep dust and water out as best as possible.
- its worth checking the vehicles trailer wiring loom protection. I added protection to the van, didn't think of the vehicle
- remember to activate the Manual Brakes before leaving home
- this is the important one, check that you have actual voltages going to the brakes. This is tricky for some controllers, some don't show this. In our situation we could have got on the road thinking everything was ok. Under normal circumstances the van generally feels good behind the Prado, and I sometimes don't really feel the van pulling the Prado up with normal braking. But by missing the Brake signal to the controller it never knew I was braking and would never have activated the trailer brakes. No Fault actually showed up on the controller, as far as it was concerned everything was ok, it doesn't know it isn't getting a Braking Signal from the vehicle. Out of curiosity I had a look at the Redarc Tow Pro Manual and it appears its LED changes colour when the brake is applied. Would recommend looking for that when you first get in the car with van connected if you have that model.
As for the P3, I will be looking for the holding voltage on the P3's display religiously from now on.

 

[Kenshi123]

Glad to hear that you solved the problem and got back on the road @Holden_man. I am really glad I read this as I haven't really thought about any protection for the wiring loom in the prado. Will be sure to sort something out before our big trip. Thanks heaps for sharing mate!

 

[dagree]

Good to hear things got sorted easily @Holden_man ..... A good reminder for us all to not take things for granted!

 

[Holden_man]

One thing worth mentioning is a big tick for the Tekonsha P3. The information it gives you is worth digging into a bit more, and something I didn't even know existed until I had a problem.
To get to these you go via "help"


then to "troubleshoot"


From here you can check the "Stoplight", "Battery", and "Output" Voltage as well as "Output Current"

The Output current would be handy to check if all brakes are there, and not missing due to broken wiring.
As long as you take an initial reading when all brakes known to be connected, resistance check can confirm this, then checking output current at a set voltage say 5V will allow for quick easy checks down the track while on the road.

 

[Bellbirdweb]

Had a similar experience on Thursday, pulled the van out hooked it all up, started down the street, and no brakes on the van.

I have a Redarc TowPro, and it was flashing 3 red and 1 orange light. Called Redarc and they told me it was a 'wiring' fault.

Checked the plug and socket on the 12 pin as I has been playing around with it fitting my reversing camera and thought I may have damaged a wire but found nothing.

Noticed I had no brake lights to van or car.

Hunted out the manual as I couldnt find the brake light fuse on the cruiser.

Mr Toyota decided to put that fuse in the 2nd fuse box behind the left kick panel that requires dismantling of a good part of the interior to access.

Found the fuse and yes it was melted.

I replaced it and reassembled the car and we were on our way.

It only cost me 1 hour so not quite as bad as you @Holden_man but good to know where all of the components are when fault finding.

 

[Dean Anderson]

Coming down Eungella-Mackay Road yesterday (short but really steep range). Redarc Towpro decided not to work. Blue light on (indicates its working OK), no brakes on the van apart from pushing the emergency which jambs the van brakes on lock....No where to pull over....Rear brakes on the Cruiser smoking something chronic (and probably causing damage).

Eventually pulled over and turned it on manual for the rest of the range.... Had to recalibrate at the bottom of the hill and it worked fine on a level surface....Car is in at ARB getting the unit replaced with a Towpro Elite as asked for and charged for by Toyota when the vehicle was purchased. At least the Elite shouldn't have a calibration problem. Will then go through the refund rigmarole with Toyota.

The Towpro unit played up months ago and I had to disconnect to reset it before it would work.

Haven't had any luck with Redarc products..... The solar controller also played up twice and have written it off as a joke....Will stick with the $36 Chinese one that I have (it works great).