TOWING LIGHTS WIRING (2012 Superb Estate Tdi.)

[nige8021]

10 minutes ago, Derbyshirebod said:

There's not really that many alternatives other than to cut and solder. It's not like these particular connections are subject to the elements. Agreed they are cheap and nasty. 

 

Use something like these https://www.ebay.co.uk/itm/261507747262?hash=item3ce3138dbe:g:WTEAAOSwZJdeuHqo  similar items are approved for wiring repairs on Boeing & Airbus aircraft 

[Name]

OK, so tomorrow, on account of I live with a permanent light warning despite all my new LED's being LED error Canbus Free (ha) I'll replace them with standard bulbs and see if the problem persists. If it does it's the relay? So sorry to be a pain and thanks again for all the help. 

 

[Name]

2 minutes ago, nige8021 said:

 

Use something like these https://www.ebay.co.uk/itm/261507747262?hash=item3ce3138dbe:g:WTEAAOSwZJdeuHqo  similar items are approved for wiring repairs on Boeing & Airbus aircraft 

I will when I get to France and all my gear. Just want to get there 1st.

 

[Derbyshirebod]

1 minute ago, Name said:

OK, so tomorrow, on account of I live with a permanent light warning despite all my new LED's being LED error Canbus Free (ha) I'll replace them with standard bulbs and see if the problem persists. If it does it's the relay? So sorry to be a pain and thanks again for all the help. 

 

Hey you can't beat learning the hard way! :-) I had a similar painfully experience after fitting my tow bar and I was getting rear tail light warning messages on the dashboard. It wasn't anything to do with the tow bar wiring! But as DEL80Y suggested replacing the old bulbs sorted my problem :-)

[J.R.]

1 hour ago, Name said:

EDITING: If it's a question of the relay recognising resistance have I unnecessarily taken the car apart because the cause is my fitting LEDs in these rear clusters? 

 

I would put all of my money on that bet even if I cannot give you a definitive explanation of the how and why.

 

Put standard bulbs back in the and see if the trailer lighting works properly. Have you even checked that your brake and rear lights function as they should?

 

I think that I might even be able to explain the why, speculation only but it makes sense, the current to the rear light circuit is probably limited by pulse width modulation (PWM) with a correct 21 watt bulb inserted the voltage measured before the element will be 12v when the brake lights are used but drop to say 8 volt when the PWM pulsed 12v is applied for the rear lights.

 

Using much lower current LED lamps means much less volt drop so the voltage during the PWM rear light operation will be the almost the same as the constant 12v for the brake lights and above the switching threshold of the bypass relay.

Edited 6 February, 2022 by J.R.

[J.R.]

Derbyshirebod.

 

It is entirely possible that my relay did have that set up and those instructions, I am someone who only RTFM's when I have exhausted all other avenues!!!!!!!!!!

 

Molex make gycerine filled Scotchlok type connectors for outside Telecoms work, they are far superior. I bet Lee has thousands like I do!

[Derbyshirebod]

6 minutes ago, nige8021 said:

 

Use something like these https://www.ebay.co.uk/itm/261507747262?hash=item3ce3138dbe:g:WTEAAOSwZJdeuHqo  similar items are approved for wiring repairs on Boeing & Airbus aircraft 

I've just bought a box of those for when I repair my broken door loom wiring which is going to fine for straight joins.  Though I'm not sure how good they would be bodging 2 wires into one side of the connector? You'd have to use a bigger size connector than the wire you're splicing into so one side of the connector with the single wire would have to shrink down considerably more than the other side with 2 wires. Would that also affect the soldered joint ?

[nige8021]

26 minutes ago, Derbyshirebod said:

I've just bought a box of those for when I repair my broken door loom wiring which is going to fine for straight joins.  Though I'm not sure how good they would be bodging 2 wires into one side of the connector? You'd have to use a bigger size connector than the wire you're splicing into so one side of the connector with the single wire would have to shrink down considerably more than the other side with 2 wires. Would that also affect the soldered joint ?

The joint isn't a soldered one it's a mechanical crimp, so on the single wire you just double over the stripped copper so that it will be properly crimped the same as the two wires on the other end of the crimp 

[DEL80Y]

I have been using these below to good effect solder and heatshrink in one

[chimaera]

I will never understand why people mess around with bypass relays and scotchloks when Skoda make a control module designed to work with the car out of the box, no messing around. Yes it's more expensive but when  you factor in the time taken to get the damn things working I doubt you've saved much. Plus, tapping off the wires to the lights can cause all sorts of shenanigans with the bulb out warning system in the car if you're not careful.

[Derbyshirebod]

41 minutes ago, chimaera said:

I will never understand why people mess around with bypass relays and scotchloks when Skoda make a control module designed to work with the car out of the box, no messing around. Yes it's more expensive but when  you factor in the time taken to get the damn things working I doubt you've saved much. Plus, tapping off the wires to the lights can cause all sorts of shenanigans with the bulb out warning system in the car if you're not careful.

Very simple a factory fitted system is expensive! You've clearly not checked the prices out! Paying £630 with universal electrics or + £218 for vehicle specific wiring for a towbar to be put on a £1800 car quite simple maths really when I can put a new detachble towbar on my car for less than £150 is a bit of a now brainer really! The reason this thread was started by the OP would seem he's caused the problem by fitting after market LED's in his rear light clusters not realising it caused a problem until he tried using the towbar 😳  I wonder would there not have been a similar issue with the towbar electrics had an OEM controler been used 🤔 

Edited 6 February, 2022 by Derbyshirebod

[Derbyshirebod]

1 hour ago, DEL80Y said:

I have been using these below to good effect solder and heatshrink in one

Those are exactly the same as I've bought to repair my broken door wiring.

[chimaera]

12 minutes ago, Derbyshirebod said:

Very simple a factory fitted system is expensive! You've clearly not checked the prices out! Paying £630 with universal electrics or + £218 for vehicle specific wiring for a towbar to be put on a £1800 car quite simple maths really when I can put a new detachble towbar on my car for less than £150 is a bit of a now brainer really! The reason this thread was started by the OP would seem he's caused the problem by fitting after market LED's in his rear light clusters not realising it caused a problem until he tried using the towbar 😳  I wonder would there not have been a similar issue with the towbar electrics had an OEM controler been used 🤔 

I've installed the OE system on my car, it's about €300 last time I checked.

[DEL80Y]

49 minutes ago, chimaera said:

I will never understand why people mess around with bypass relays and scotchloks when Skoda make a control module designed to work with the car out of the box, no messing around. Yes it's more expensive but when  you factor in the time taken to get the damn things working I doubt you've saved much. Plus, tapping off the wires to the lights can cause all sorts of shenanigans with the bulb out warning system in the car if you're not careful.

Also adjusts the ESP with TSA (Trailer Stability Assist)

[chimaera]

A while back I had an interesting chat with the local Indespension guy here. He has a fitter who buys universal kits from him regularly and fits them to a variety of cars. This fitter had a very expensive mistake on a Ford when he tapped off a particular wire in the vehicle. There had been a change in the wiring in the vehicle during product which meant that a wire that used to work fine for him instead resulted in the towing electrics blowing a few control modules the cost of which he had to eat, somewhere around €1500 in the end.

4 minutes ago, DEL80Y said:

Also adjusts the ESP with TSA (Trailer Stability Assist)

Yup, and the alarm integration is nifty too.

[Derbyshirebod]

14 minutes ago, chimaera said:

I've installed the OE system on my car, it's about €300 last time I checked.

https://www.towbarexpress.co.uk/skoda-superb-detachable-swan-neck-towbar-superb-hatchback-estate-3v/?gclid=EAIaIQobChMIot7Nvebr9QIVF41oCR161QxLEAQYASABEgJuC_D_BwE

[chimaera]

2 minutes ago, Derbyshirebod said:

https://www.towbarexpress.co.uk/skoda-superb-detachable-swan-neck-towbar-superb-hatchback-estate-3v/?gclid=EAIaIQobChMIot7Nvebr9QIVF41oCR161QxLEAQYASABEgJuC_D_BwE

That's towbar plus electrics plus fitting, pretty good value actually when you price up the components and the labour time to fit everything. The €300 figure was for the electrical kit on its own.

[DEL80Y]

Just watched a video on Skoda Trailer Assist which uses the park assist to reverse your trailer 

Modern technology
 

 

[Name]

18 hours ago, Derbyshirebod said:

Yes the exact same bypass relay as I have. Though if you've not got the grey wire from the bypass relay connected to the cars blue wire to the reverse bulb then the trailer reverse lights won't work. Not that many trailers have reversing lights. The way the relay works is quite simple really. With only the common red wire from the brake  circuit when the car side lights are on then it detects the reduced voltage and only supplies a current to the trailer board side light circuit. When it detects the higher voltage when the brakes are applied it only supplies a current to the trailer board brake light circuit. When the relay detects the higher combined voltage from both brake and side light circuits the relay then supplies a current to both the trailer board brake and side light circuits. This is a much better system than the old way of splicing into the cars wiring loom and there isn't a voltage drop as the bypass relay has it's own voltage supply so you don't get dim or flickering bulbs on the trailer board lights.

 

I don't see why you think taking a feed from the back of the auxiliary socket is a problem? That's what J.R and I have both done. The auxiliary socket circuit is protected by it's own fuse in the car fuse box.

 

As long as you've used LED ERROR FREE CANBUS BULBs in your rear light clusters I think you should be okay? Otherwise I think you would have been getting bulb warnings on the dashboard? As in the photo. But yes maybe a good idea to put the original bulbs back in and see if the trailer board side light do work correctly before splashing out on a new relay ! Which are about £30.

 

 BTW I did say disassembling the boot cover panels was a PITA ! 😅😅

 

 

 

 

Let this be a lesson to all fiddlers. This morning I left the intense reversing light LED's in place as I did the fog. Yes, these Canbus OK lights raise the instrument alarm but I'm OK living with that as I am the obviously not OK Canbus OK front Fog light LED's (bloody joke). I changed the brake LED's (yes, Canbus OK ..... ha) bulbs back to the standard 16w and, Presto, the entire setup functions as it should with black and brown powering sidelights and the red, dedicated brake. I have learned a lesson and while I hope other LED fiddlers learn about this before they fit towing harnesses I would like to thank all contributors to my plight. God Speed.

[chimaera]

6 hours ago, Name said:

Let this be a lesson to all fiddlers. This morning I left the intense reversing light LED's in place as I did the fog. Yes, these Canbus OK lights raise the instrument alarm but I'm OK living with that as I am the obviously not OK Canbus OK front Fog light LED's (bloody joke). I changed the brake LED's (yes, Canbus OK ..... ha) bulbs back to the standard 16w and, Presto, the entire setup functions as it should with black and brown powering sidelights and the red, dedicated brake. I have learned a lesson and while I hope other LED fiddlers learn about this before they fit towing harnesses I would like to thank all contributors to my plight. God Speed.

The OEM electrics would probably have been fine as all the control signals for the trailer lights come down to the controller via CANBUS rather than tapping off the rear light cluster.

[J.R.]

23 hours ago, chimaera said:

I will never understand why people mess around with bypass relays and scotchloks when Skoda make a control module designed to work with the car out of the box, no messing around. Yes it's more expensive but when  you factor in the time taken to get the damn things working I doubt you've saved much. Plus, tapping off the wires to the lights can cause all sorts of shenanigans with the bulb out warning system in the car if you're not careful.

£300 you say, my relay was less than £30 and came bundled with the £115 towbar, by far the most I have ever paid in my life, it took no time to get working and was a much faster install than the VAG control module which requires wiring being run to the fuseboard at the front of the vehicle unless you have specified Trailer Preparation from new and forked out £100's for that. plus there would then be recoding, I have VCDS but another DIY'er would have to pay.

 

The new high impedance electronic relays are far more reliable than the old piggyback style that loaded each light circuit and required messing around with coil spacings for the audible indicator warning.

 

Tapping off the lights create no shenanigans whatsoever, the control current for the transistor is miniscule, using an old style unit or direct wiring to the towing socket would, as the OP can attest using LED bulbs does cause major problems but the towing bypass relay does not.

 

I do not use Scotchloks but a glycerine filled Molex telecoms quality equivalent .

Edited 7 February, 2022 by J.R.

[CosmoJ]

Fortunately I haven't had to pay anything. Bought this particular car as it was fitted with the rig. I pulled everything apart to gain access to the relay (I see they are £23) only to find that everything works just fine now that I have put back the 16w brake light bulbs. As to using the relay with an independent power supply with lamps activated by initiating bulbs in the cluster it's a great idea methinks.