I've got myself a towbar for the 500 to use a bike carrier and need to sort out connecting the towbar electrics. I have everything sorted out except the number plate light as its in the tailgate. Does anyone know where I can pick up the wiring for the tailgate? I don't want to remove any more of the interior than I need to.
Technical Towing Electrics
- Thread starter DWaldie
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Technical
Towing Electrics
Surely unless the tow bar and bike carrier obstruct the number plate so you need an extra number plate with lighting then no need for towbar wiring, unless you intend to buy a trailer also.
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The number plate lights should come on and off with the tail lights so there would be no harm in just tapping into that.
The number plate light can be picked up in the roof, i'm not sure on the 500 but presume its like other cars it might run along the side of the roof from the fuse box so unless you want to go digging around potentially damaging the roof lining, then just use the tail lights.
The other advantage of these is you can still open the boot as the cycle carrier tends to tip away from the car so allow access without having to take all the bike off.
The old style that you strap to the car and hang the bikes off the back are becoming less common now
The number plate light can be picked up in the roof, i'm not sure on the 500 but presume its like other cars it might run along the side of the roof from the fuse box so unless you want to go digging around potentially damaging the roof lining, then just use the tail lights.
I think most if not all Towbar mounted bike carriers look like this these days with the additional light bar on the back. Given that most bikes will obscure the rear lights and the number plate and in some cars just the tow bar on its own can obscure the number plate, it is almost always the case you'll need to plug the cycle carrier into towbar electrics.Surely unless the tow bar and bike carrier obstruct the number plate so you need an extra number plate with lighting then no need for towbar wiring, unless you intend to buy a trailer also.
The other advantage of these is you can still open the boot as the cycle carrier tends to tip away from the car so allow access without having to take all the bike off.
The old style that you strap to the car and hang the bikes off the back are becoming less common now
I don't like the strap ones , daughter had a Tiguan and the bike rack was pulling on the tailgate, I got one from a Motorhome that went on the little Nissan towbar, even with three bikes on it, it is high enough to not obscure the numberplate. Mind you it was a plate fitted behind the towbar ball that you slotted two L shape horns in to, so no good for detachable balls like most later cars.
Number plate and lights on the 500 are higher up just below the back window so you’d need to mount bikes really high on the back not to obscure them
I did wonder about tapping into the tail lights but wasn't sure if it would affect the canbus. If yours doesn't, I guess mine shouldn't
If you are using a bypass relay then in theory you don’t need to tap into the tail lights or the number plate light, just connect the wire for the tail lights to both pins on the socket for the rear lights and the number plate light
Actually scrub that, if it’s a 7pin. Socket then you shouldn’t need to tap into the number plate light at all, it will probably link the number plate light and the tail lights in the light board of the cycle carrier
@PuntoHowTo I think you've answered my question. When I get back from my hols, it'll be bumper off and towbar on. Apparently the 500 can (legally) tow 800Kg. I'll not be trying that in a hurry
Just check the “nose weight” which is the max downwards weight the towbar can take.
If you’re mounting a couple or three modern e-bikes/e mountain bikes you can easily exceed the nose weight, especially also taking into account the weight of the rack itself
If you’re mounting a couple or three modern e-bikes/e mountain bikes you can easily exceed the nose weight, especially also taking into account the weight of the rack itself
the rack is 19Kg, my bike is 24Kg and my wife's is 22Kg. The nose weight limit is 80Kg, so I should be fine. Bet it'll understeer in fast corners though
You might be able to pop a wheelie
I'd be using relays for everything, the thought of the extra loading on the tiny BCM pcb tracks turning them into heaters would worry me, I'd also use a diode across the relay coil to stop huge spikes back to the BCM?
Or just use a “bypass relay” which isn’t a relay per se but an electronics device which senses which lights are on and then turns on power to the towbar electrics.
It’s pretty standard these days, anything else will result in bulb failure warnings (“canbus errors”) even just a normal relay in the lighting circuit would trigger a bulb failure warning.
They look something like this
You’ll see it takes a 12v supply directly from the battery, this is what it used to switch on and power lights, it has its own earth, the other wires just sense what lights are activated and the module replicates that through the pins on the towbar socket
It always amused me that a Citroen 2CV could legally tow a small caravan and yet a more powerful early Ford KA could not by design.@PuntoHowTo I think you've answered my question. When I get back from my hols, it'll be bumper off and towbar on. Apparently the 500 can (legally) tow 800Kg. I'll not be trying that in a hurry
Strangely although I was told this soon after they came out, I see online some say they can and some say different?
"some cars are not permitted to tow at all, including the Ford Ka and the Vauxhall Tigra."???? Mind you there was more of a chassis to bolt them to on the 2CV.
My wife's 500 can tow with a 70hp engine and no torque. My Mini Cooper S with 190hp and 280Nm cannot. It comes down to the realities of where to bolt on a towbar. The Mini has central exhausts, the 500 doesn't. I bet it's some similar reason for the Ka.It always amused me that a Citroen 2CV could legally tow a small caravan and yet a more powerful early Ford KA could not by design.
Strangely although I was told this soon after they came out, I see online some say they can and some say different?
"some cars are not permitted to tow at all, including the Ford Ka and the Vauxhall Tigra."???? Mind you there was more of a chassis to bolt them to on the 2CV.
Thanks for the help in getting my issue sorted (hopefully!).
Ill report back
