Towbar wiring in - 13 pin electrics.
Discussion
We have a 2005 Honda FR-V 2.0 VTEC that we are going to use as our tow car for our lightweght Eriba Triton.
The car is worth £2k tops, just had a quote of £450 to fit the towbar - a bit more than I expected. I can get the towbar and electrics myself, delivered for £170. Burning question: is there really £280 of labour involved in fititng one of these?
I am a competent spanner-er - have no qualms about removing the bumper, fitting up the bar itself, but am a bit in the dark about modern(ish) car electrics. The last time I helped my dad fit a tow bar as a teenager it was a spider's web of scotchlocks in the boot of his '82 Granada, but I gather things have moved on since then!
I was hoping the wiring would be 'plug and play' - there are two unused connector plugs tucked away behind the plastic cover for the RHS tail light which the handbook says are for towing a trailer but not sure if this is what I need for a 13 pin socket for powering the caravan lights and the fridge/charging leisure battery etc.
The car is worth £2k tops, just had a quote of £450 to fit the towbar - a bit more than I expected. I can get the towbar and electrics myself, delivered for £170. Burning question: is there really £280 of labour involved in fititng one of these?
I am a competent spanner-er - have no qualms about removing the bumper, fitting up the bar itself, but am a bit in the dark about modern(ish) car electrics. The last time I helped my dad fit a tow bar as a teenager it was a spider's web of scotchlocks in the boot of his '82 Granada, but I gather things have moved on since then!
I was hoping the wiring would be 'plug and play' - there are two unused connector plugs tucked away behind the plastic cover for the RHS tail light which the handbook says are for towing a trailer but not sure if this is what I need for a 13 pin socket for powering the caravan lights and the fridge/charging leisure battery etc.
I know alot of people who have self fitted, not sure I trust my own skills on mine to do it.
£450 is about right to be fair.
Not all cars have all the pins wired - for instance my Audi came with a factory fit removeable towbar but Audi in their wisdom do not connect the pin to make the fridge work on journeys. It went back in after a few strong words with the dealer who then wired it to work.
The range rover sport previously (And all Land Rovers from my knowledge) fully wire their pins for caravans, not just trailers.
Whats the worse that can happen if you do it yourself?
£450 is about right to be fair.
Not all cars have all the pins wired - for instance my Audi came with a factory fit removeable towbar but Audi in their wisdom do not connect the pin to make the fridge work on journeys. It went back in after a few strong words with the dealer who then wired it to work.
The range rover sport previously (And all Land Rovers from my knowledge) fully wire their pins for caravans, not just trailers.
Whats the worse that can happen if you do it yourself?
I did my own fitting with a towbar and a couple of relays from Towsure. One relay to sense the CANBUS lines for side light/brake light/indicators and one to power the fridge and leisure battery charger. If you've got a socket for the lights you might not need the first relay.
Although I fitted it, I'm not that convinced about the need for the fridge/battery charger relay. I bring our fridge down to temperature a couple of days before a trip (through the mains hook-up), and the battery is always on trickle charge. Unless you're doing a really long trip, even when it's switched off the fridge will stay cold for a good while, and the battery will keep its charge. I also suffered an inexplicable flat battery on the car the morning after a three-hour tow, so I'm now suspicious about that aspect of it.
Although I fitted it, I'm not that convinced about the need for the fridge/battery charger relay. I bring our fridge down to temperature a couple of days before a trip (through the mains hook-up), and the battery is always on trickle charge. Unless you're doing a really long trip, even when it's switched off the fridge will stay cold for a good while, and the battery will keep its charge. I also suffered an inexplicable flat battery on the car the morning after a three-hour tow, so I'm now suspicious about that aspect of it.
You probably don't really need the battery charge and fridge feed - I don't power up our van in transit either. The fridge holds its pre departure temperature for a good six or seven hours if the door is left closed. That is long enough for all but our longest runs the length of the UK where the fridge would be empty anyway.
What you would be missing if the car is plug and play for a trailer only, is a reverse light feed. Pretty sure you could take a feed from the correct wire at one of the tail lights of the car down to the 13 pin socket for this though.
What you would be missing if the car is plug and play for a trailer only, is a reverse light feed. Pretty sure you could take a feed from the correct wire at one of the tail lights of the car down to the 13 pin socket for this though.
ALY77 said:
You probably don't really need the battery charge and fridge feed - I don't power up our van in transit either. The fridge holds its pre departure temperature for a good six or seven hours if the door is left closed. That is long enough for all but our longest runs the length of the UK where the fridge would be empty anyway.
What you would be missing if the car is plug and play for a trailer only, is a reverse light feed. Pretty sure you could take a feed from the correct wire at one of the tail lights of the car down to the 13 pin socket for this though.
I've only been towing a caravan for a few months and so far have succesfully avoided having to reverse the bWhat you would be missing if the car is plug and play for a trailer only, is a reverse light feed. Pretty sure you could take a feed from the correct wire at one of the tail lights of the car down to the 13 pin socket for this though.
d for any appreciable distance, and long may that continue. I'd rather shove it by hand or use the motor movers.Halmyre said:
I've only been towing a caravan for a few months and so far have successfully avoided having to reverse the bd for any appreciable distance, and long may that continue. I'd rather shove it by hand or use the motor movers.
OP, it would appear that so long as the items this can check work, you'll get through an MOT www.shop.fta.co.uk/samples/TST22.pdfd for any appreciable distance, and long may that continue. I'd rather shove it by hand or use the motor movers.So far as reversing is concerned - Make sure you can actually see along the van sides with the mirrors for going straight back, to watch for the back end wandering off in any direction it fancies and always reverse park on pitches on your offside, so you can look out the drivers side window at where the axle is. Oh, and never be too proud to pull forwards to straighten it up again and accept you will always have an audience!
Thanks for all replies so far.
I did consider one of those Seeley socket testers but they are about £60 for something I would use only occasionally. I would need one though, because for logistical reasons the van is going to be in one part of the country and me another at the point of towbar fitment, so no opportunity to test the wiring with the van in place.
A bit of additional surfing has got the fitted price down to £399 so I'm going for that.
As far as powering the fridge goes that is a nice to have, but it's more the charging of the fitted leisure battery I'm after. We're primarily going to use it for music festivals which by their nature are temporary campsites without electric hookups, so as long as that battery gives us enough for a bit of lighting/phone charging we should be OK.
I did consider one of those Seeley socket testers but they are about £60 for something I would use only occasionally. I would need one though, because for logistical reasons the van is going to be in one part of the country and me another at the point of towbar fitment, so no opportunity to test the wiring with the van in place.
A bit of additional surfing has got the fitted price down to £399 so I'm going for that.
As far as powering the fridge goes that is a nice to have, but it's more the charging of the fitted leisure battery I'm after. We're primarily going to use it for music festivals which by their nature are temporary campsites without electric hookups, so as long as that battery gives us enough for a bit of lighting/phone charging we should be OK.
Have fitted a few towbars and if, as you say, you're spanner wise, then it's not difficult and I'd say go for it, the worst that can happen is you get a bit lost with the wiring in which case an auto electrician will sort it out for you for a few quid though it really is fairly straightforward. Watched the chappie fit the bar and electrics on SWMBO's Honda Civic and it was all fairly obvious and straightforward, just locate each wire in the light cluster and scotchlock to the towbar harness.
Halmyre said:
ALY77 said:
You probably don't really need the battery charge and fridge feed - I don't power up our van in transit either. The fridge holds its pre departure temperature for a good six or seven hours if the door is left closed. That is long enough for all but our longest runs the length of the UK where the fridge would be empty anyway.
What you would be missing if the car is plug and play for a trailer only, is a reverse light feed. Pretty sure you could take a feed from the correct wire at one of the tail lights of the car down to the 13 pin socket for this though.
I've only been towing a caravan for a few months and so far have succesfully avoided having to reverse the bWhat you would be missing if the car is plug and play for a trailer only, is a reverse light feed. Pretty sure you could take a feed from the correct wire at one of the tail lights of the car down to the 13 pin socket for this though.
d for any appreciable distance, and long may that continue. I'd rather shove it by hand or use the motor movers.Some mechanic fitted the towbar to my old scenic but would not touch the electrics due to CANBUS etc.
I fitted it with a bypass relay. Requires a lot more wiring but it's better to be safe.
http://www.ebay.co.uk/gds/Bypass-Relays-Explained-...
I fitted it with a bypass relay. Requires a lot more wiring but it's better to be safe.
http://www.ebay.co.uk/gds/Bypass-Relays-Explained-...
ColinM50 said:
Have fitted a few towbars and if, as you say, you're spanner wise, then it's not difficult and I'd say go for it, the worst that can happen is you get a bit lost with the wiring in which case an auto electrician will sort it out for you for a few quid though it really is fairly straightforward. Watched the chappie fit the bar and electrics on SWMBO's Honda Civic and it was all fairly obvious and straightforward, just locate each wire in the light cluster and scotchlock to the towbar harness.
Anything which is scotchlock will fail, garanteed. The only option any auto electrition should use is solder...Also, tapping in to rear light clusters may overload the OEM wiring if not using LED lights on the tow vehicle. You need a switched relay. http://www.towsure.com/fit_a_multiplex_bypass_rela... Hopefully the battery is in the boot, if not it gets more complicated...
I've fitted a few now and I always pay more for plug-in electrics. On the Subaru, Nissan and Toyota it just worked. Mercedes need STAR coding but the results aren't always consistent unless you pay for their wiring looms, even if you buy a "dedicated" loom from a 3rd party.
You could save money by fitting the towbar yourself, wiring up the socket and presenting the car-end of the loom ready for an auto electrician to connect it up. That would likely cost siginifanctly less (unless Mercedes - ask me how I know).
You could save money by fitting the towbar yourself, wiring up the socket and presenting the car-end of the loom ready for an auto electrician to connect it up. That would likely cost siginifanctly less (unless Mercedes - ask me how I know).
Thurbs said:
nything which is scotchlock will fail, garanteed. The only option any auto electrition should use is solder...
Absolute rubbish. Soldered joints are considered technically the worst joint, vibration causes them to fail On aircraft a soldered joint would ground the plane. And as regards MoT, when did you ever see a tester take light clusters out to check the wiring? AFAIK, they're now even allowed to remove any panel for any purpose, least of all and item that isn't in the test remit and towbar electrics aren't in their remitColinM50 said:
Absolute rubbish. Soldered joints are considered technically the worst joint, vibration causes them to fail On aircraft a soldered joint would ground the plane. And as regards MoT, when did you ever see a tester take light clusters out to check the wiring? AFAIK, they're now even allowed to remove any panel for any purpose, least of all and item that isn't in the test remit and towbar electrics aren't in their remit
When listening to ATC, I often hear "cleared for scotchlock takeoff" 
love your argument...Rather than me explain, here is someone on the internet: http://tech.bareasschoppers.com/resources/the-prob...
ColinM50 said:
Thurbs said:
nything which is scotchlock will fail, garanteed. The only option any auto electrition should use is solder...
Absolute rubbish. Soldered joints are considered technically the worst joint, vibration causes them to fail On aircraft a soldered joint would ground the plane. And as regards MoT, when did you ever see a tester take light clusters out to check the wiring? AFAIK, they're now even allowed to remove any panel for any purpose, least of all and item that isn't in the test remit and towbar electrics aren't in their remitSolder is way more reliable than scotch locks (good article explaining posted above)
How many scotch locks have you seen in aviation engineering?? Crimped, heat shrunk, inline splices are used - a completely different thing.
Towbar electrics (13 pin) are a tested item on the MOT.
Edited by DuraAce on Tuesday 30th May 16:40
OTOH, my dad's been caravanning for 40 years and alsways used scotchlocks in his electrics, with nary a problem. There must be millions of the little buggers out there, but you only hear about the bad ones. I wired up my caravan electrics with them and I would have been carted off to the funny farm if I'd attempted to form soldered connections into the wiring loom. It's bad enough in a nice roomy brightly lit lab with adjustable spring-clip stands to help you.
DuraAce said:
I think your post contains most of the rubbish!
Solder is way more reliable than scotch locks (good article explaining posted above)
How many scotch locks have you seen in aviation engineering?? Crimped, heat shrunk, inline splices are used - a completely different thing.
Towbar electrics (13 pin) are a tested item on the MOT.
The article you refer to is about pushbike or maybe motorbike electrics, not quite what the title would have us believe, i.e. choppers. I thought at first it was about helicopters. Not quite the same ruggedness needed on bikes as Helicopters is there? I do agree that in aviation only crimped joints are used, never seen a scotchlock used and would think any lekky seen with a scotchlok in his toolbox would be dismissed on the spot. I worked in Toulouse at Airbus for six years on the early A380 build (up to MSN 76 I think), and everything was crimped. We ran refresher courses every six months testing hand crimp skills and techniques. I never said aviation uses scotchloks, what I said was that they don't use solder joints due to failures with vibration. Crimp every time. Solder is way more reliable than scotch locks (good article explaining posted above)
How many scotch locks have you seen in aviation engineering?? Crimped, heat shrunk, inline splices are used - a completely different thing.
Towbar electrics (13 pin) are a tested item on the MOT.
Edited by DuraAce on Tuesday 30th May 16:40
Back to the point though, I've currently got two cars with towbars and both have their electrics scotchlocked. Tester has NEVER looked at or asked about how they're wired. I stand to be corrected and will buy you a virtual pint if you can tell me the section of the MoT which specs the towbar electrics and bans scotchloks.
Gassing Station | Tents, Caravans & Motorhomes | Top of Page | What's New | My Stuff