I'm guessing there are a few peeps on here who have car electronics which will (or are supposed to) detect a failed bulb on the van and show a corresponding warning light in the instruments.

Of those that do, has anyone had a 'failed bulb' warning because the van's high level Hella brake light uses very low wattage (and low-resistance) LEDs rather than incandescent bulbs, and the car's electronics think the light has conked?

If you did, how did you cure it?

Thanks

Pete

Thanks John

I'm putting the cart before the horse a little bit on this one I admit, because other than to briefly test the new car's towbar factory wiring I'm not sure what's happening yet...

I hooked up the van primarily to establish whether or not Audi had finally seen the light and provided all the connections necessary to run the fridge and charge the battery when towing, something they (and VW and Skoda and Seat) haven't always done in the past, often resulting in needless faff, argument and sometimes even extra expense.

In that regard, it's an unqualified success - I'm getting a nice, fat 14.7v at the van's battery terminals with the engine running, and the fridge works too. I briefly checked the lights, and as far as I could see in the limited time I had, all the road lights worked including cutting the car's rear fog but illuminating the van's as intended. I admit, to my shame, that I didn't notice whether or not a bulb out warning came on when I pressed the brake pedal, mainly because I stuck my leg in the car to do it rather than sitting behind the wheel.

However, while faffing about with some diagnostic software connected to the car's OBD port today I noticed that it had logged a past fault with the trailer brake lights. Now I know that all three van brake lights work properly (i.e. the two incandescent ones and the high-level LED), so I reckon the car's electronics picked up the high level light as malfunctioning - not because it was, but because LEDs don't offer the resistance that a proper filament bulb does, thereby making the car think the bulb had packed in.

This is not an uncommon problem, both with cars alone and with those towing LED road light-equipped caravans.

Drivers who replace traditional indicator, tail and brake light bulbs with LEDs often suffer from it to varying degrees depending on the make and age of the car concerned. The solution usually involves swapping them to supposedly CANBUS-compatible bulbs (CANBUS being the car's electronic system) or wiring in a simple load resistor to fool the CANBUS into thinking that the bulbs are still high(er) resistance incandescent ones.

When it comes to caravans, people seem to either live with the dash warnings (that would drive me nuts), get modifications made to the car's towbar wiring (something I don't want to do) or, least helpfully from my point of view, get the caravan dealer to fix it.

Anyway, at some point my car has picked this up, and all I'm doing really, since it's peeing down and thoroughly miserable outside, is fritter away a couple of hours attempting to head off a potential snag.

So, after all that, all I wondered was whether anybody else had come across this.

Incidentally, having seen (if not fully used) this car's tow hitch, I can't help but think it was worth the money it cost to have the full factory installation.

The hitch is completely hidden behind the rear valance when not in use, and is released by a very posh switch with a built-in LED telltale in the side of the boot which flashes when being deployed but lights steady when the hitch is correctly locked at either end of its travel. Pull the switch and the towball swings down into position; pulling the switch again releases it and allows it to be swung up into its hiding place.

The hitch itself is a work of art - the 13 pin socket is built into the side of the casting, and it's got a proper breakaway cable loop built in. It's the same as this one, but with the socket on the other side. It's so swanky I can't bring myself to take a strip of Emery to that lovely black ball just yet.

Hopefully the car will pull the van okay. We'll find out once it's got a few more miles under its belt.

But that's a minor issue...

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New car?

Zitat

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Hopefully the car will pull the van okay. We'll find out once it's got a few more miles under its belt.

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Have we missed something?

Randa

I have tow ball envy. I like the 13 pin electric connection and the break-away cable eye. Very nice.
It sounds as if the VAG group are finally supplying "full functunallity" on the 13 pins and about time.
What Audi have you got this on?

Colin

Quote: eribaMotters wrote in post #5

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I have tow ball envy.

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Quote: eribaMotters wrote in post #5

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What Audi have you got this on?

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Must be something about Audi that runs in the blood. My sister is on her 3rd A3. The current is the 300hp S3, I think. [had a new engine at 6 months when it blew up - her words]. Brother in law is on an A4 allroad, after clocking up not sure if it was 280k or 380K in an 07 A3 4wd diesel. The niece has an A1.
I will be considering a Q3 to replace the Yeti when the day comes.

Colin

Colin

I ate my hat on Saturday morning.

It wasn't that bad really, though I did get a touch of flatulence later in the day.

I was wrong about the high-level brake light being LED, at least on our van. It's a stock Hella unit, a standard fitment on lots of vans of this vintage, but it has seven little 3W incandescent bulbs. So I was even more wrong about the high-level light (and its nonexistent LEDs) causing a trailer brake light error to be stored in the car's ECU.

I tried it again this weekend, and everything worked properly with no errors anywhere. I suppose it's possible that the error code stored by the car was left over from when the towbar electrics were coded, but it doesn't matter now because it's all spiffy.

Mainly in the interest of increasing Mr Motters' towball envy levels, here are a couple of photos of the hitch on our car...

The hitch with its dinky little cover:

Cover.jpg - Bild entfernt (keine Rechte)


That lovely new ball...

New ball.jpg - Bild entfernt (keine Rechte)


The release switch in the side of the boot:

switch.jpg - Bild entfernt (keine Rechte)


The hitch partly retracted:

Swivelled.jpg - Bild entfernt (keine Rechte)


The back of the car when the hitch is fully retracted:

Rear.jpg - Bild entfernt (keine Rechte)


Looking up into the recess in the valance with the hitch partly retracted, these two pictures show how the hitch rotates on a whopping great cast boss, and how the angle of that boss allows the hitch to slide away into what's actually quite a narrow slot. It's a pretty hefty bit of kit, but all very neat and tidy:

Hitch boss.jpg - Bild entfernt (keine Rechte)

hitch boss 2.jpg - Bild entfernt (keine Rechte)



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Quote: Deeps wrote in post #11

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Nice but I wonder what was behind the thinking by adding an eye to the towball. I wonder if perhaps the VW group misunderstood the bit about the breakaway cable not being looped around a removable towball but instead an alternative fix point should be provided on the chassis of the car.

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Do you get a removeable cover to go over the cut out to stop your ball from getting dirty?
You wouldn't want to get get any nasty grit on it would you.

Colin