Electric trailer brakes No4

[Pedro_The_Swift]

I hooked up the van this morning to set up the new P3 controller,, did the "slide the manual control at 25mph" test expecting huge clouds of blue smoke only to find very little braking,,
The P3 showed the full 6 amps were being sent.
The van does assist when pulling up, but was never great,, one reason I bought this P3.
All 4 shoes/drums show usage (no glazing)but could be anything up to 20 years old. The wiring on the Disco would be marginal (current wise)at best, I have adjusted the shoes since purchase.
I would imagine the van brakes wires would be unchanged since manufacture, but you dont need starter cable to carry 6 amps over 6 metres.

The van pulls up ok at boost 2.
Any P3 Pro's out there??

[wrinklearthur]

I hooked up the van this morning to set up the new P3 controller ---- showed the full 6 amps were being sent.
but you dont need starter cable to carry 6 amps over 6 metres.

There is considerable amount of resistance using thin / lightweight copper wire over that distance.

I would rewire using at least 5 mm² and run both a power and earth from the controller to the brakes.

Always use a fuse at the closest point practical ,where you pickup your power from and to safeguard your vehicle in the event of a crook vehicle earth, I would use the same size fuse that is used in the power line, placing one in the earth line to the trailer as well.
.

[smally4.6]

Hi Pedro
Whats the output voltage being sent to van
I have a P2 brake controller and my display show output in volts sent to van..
I don't know if this helps, this is the settings I use with my setup
My van weight is around 1.7t loaded and is a single axle off road coromal pop top.
I have my P2 set at 6.7 volts ,( max is 13 volts )and on boost 2
I have found this setting ideal towing on the highway , can feel the van braking more than the disco...
When I'm doing more stop start driving (city/bigger towns) I turn the boost off
Cheers smally

[Pedro_The_Swift]

Its 6.5 at the moment,,
is there an upper level?

when doing a normal car+van stop its saying around 2.5 amps??

I think I need to spend more than 5 minutes trying things,,:angel:

[smally4.6]

Its 6.5 at the moment,,
is there an upper level?

when doing a normal car+van stop its saying around 2.5 amps??

I think I need to spend more than 5 minutes trying things,,:angel:

With the P2 you can adjust the voltage level up to 13 volts.....
I dont know how you do this with the P3...

cheers smally

[robbotd5]

Pedro.
I had this drama initially with my P3. I simply did not have the voltage high enough to suit my van. I set it up as per the manual and started on the default level. Boost 2. I found this setting to be entirely ineffective for my rig (23ft Retreat Daydream dual axle 2381kg). The initial bite of the van brakes quickly subsided and the D2a was struggling to pull it up. So I upped the voltage to 9.5, what a difference! Ended up backing it off to 9 and boost level to 1. Very safe and confident braking now. The van leads the car as it should and pulls up in no more distance than the car alone would.
I found B2 to be too severe, especially at low speeds such as in traffic or in caravan parks.
So mate, up the voltage and see how you go. You can go up to 12.8V. But you will only need 9 max by the looks of your van.
Regards
Robbo

[Graeme]

All 4 shoes/drums show usage (no glazing)but could be anything up to 20 years old.What is the condition of the drum surface where the magnets rub? My 1990 van's linings and drum were good but the cause of poor brakes was the badly worn surface for the magnets and the badly worn magnets. With new drums the wheels will lock on gravel if the emergency lever is used and that's with 31" tyres. Previously with 26" tyres the brakes wouldn't even prevent the van and D4 from moving whilst at idle in D.

[Pedro_The_Swift]

Just been out for another play,,

had 5 or six goes at 9V and it now stops much better,,

on one wheel.

the rear drivers side was hot, the rest were luke warm at best.
It figures as the first time I hit the slide control with 9V dialed in the van kicked sideways just enough for me to notice.

The question is,,
why only one?

[Pedro_The_Swift]

Anybody know how much you can skim off the magnet/drum surface?

or,
do 10" drums fit inside a 14" rim??

[robbotd5]

Hey mate sounds to me you just need to adjust them. By all means take the drums off and inspect the internals. To adjust them, jack the wheel off the ground, making sure it is attached to your Disco, pry off the dust cover and adjust starwheel up until the wheel locks, then back off a couple of turns until the wheel rotates with a minimal interference. Repeat this times 4 and go for another run. Providing the magnets and linings are still ok, I reckon you will nail it. Take notice of the wheel that was braking (the hot one), it will not require as much adjustment as the others.
Regards
Robbo

[Pedro_The_Swift]

I should just be able to adjust the star wheel,,
the trouble is I've already done this,,

does the activation arm lose leverage the further it has to move?:confused:

does the arc of the arm hit the stub at the end of its travel?

[robbotd5]

Ok, goal posts moved. To both of your questions, yes both seem possible, you may need to delve deeper. Check wear on drums, magnets and linings. What brand are they? Not real familiar with the Golf vans. May be the best course of action is to renew all serviceable parts in the braking system so you have a clean slate so to speak. It may also be a wiring issue but on 3 wheels? I recently rewired my brakes. Removed the screw wire connectors that were already corroding and replaced with spade connectors tightly wrapped up in electrical tape.
Regards
Robbo

[Pedro_The_Swift]

Yahoo! Sharkies score!!
opps sorry Robbo,,:angel:

I think I'll adjust again,,
and while I have it in the air,
I'll check voltages, controller Vs magnet.

if all that is good, its gotta be magnets?

[robbotd5]

No worries mate, Nick jnr on at our house!!!!. Solid plan. Keep me in the loop ok?
Regards
Robbo

[wrinklearthur]

It still sounds like a dose of a crook current path to me.

Make sure your brakes are adjusted correctly by all means, but I do think that you need to check that the wiring has a good earth connection at the brakes on both sides, then the earth wiring continues back to the earth of the car.

Don't forget Kirchoff's Law.
.

[Graeme]

do 10" drums fit inside a 14" rim??
Yes, that's what my Coromal pop-top had.

[Pedro_The_Swift]

Ok.
here my one dum question for the day,,

if the controller is putting out 2.3a (say) does each magnet get that?
or is that amount split over the 4 wheels?

[Pedro_The_Swift]

Adjusted the 3 non working wheels,,
and bingo!
I now have TWO working brakes,,
and,
of course,
they are both on the one side:angel:

Looks like another adjustment session is in order.
Its a complicated thing jacking up one side of a fully independent twin axle van,,
I have a 20T bottle jack that does fit inbetween the tyres,, but as the weights taken off, the rear tyre swings forward onto the jack,,,:p

I am still looking for a way to check voltages at the wheel that doesnt involve scrafing off insulation.

[NavyDiver]

TWO working brakes-Pedro_The_Swift

I was betting it was the van brakes not the D3 wiring or P3 controller :D.

My P3 on a camper trailer caused the odd error in my D3 but works perfectly otherwise. I did need to adjusting both brakes to the correct setting and play with the PS settings.

I might see lock up a second or two earlier on one side if I deliberately try to lock up! After a out in the bush rebuild of a broken spring and shock absorber I found resetting or adjusting the trailer brakes on dirt allowed me to set them almost perfectly. The trailer via the P3 Override can pull up my D3 with out braking in the car on flat roads and this is very helpful coming down a very steep slope with it behind me! :eek: