Towbar Electrics

[hinged_bap]

Warning: I'm a numpty with electrics. I have read various threads about towbar electrics and it all starts to go over my head with talk of 'can-bus', relays, reversing sensors etc. All I want to do is fit a tow bar to mount a bike carrier onto and then wire a towbar socket to accept a trailer board which is attached to the bikes on the bike rack. My car has 'bulb failure' indicators on the dashboard thingy. If I just splice into the loom for the towbar plug will all this stuff still work. I'm not worried at all about a dash warning light saying a trailer board bulb has blown and neither am i worried about reversing sensors beeping when in reverse and the bikes are mounted on the rack.
TIA

[HarryM1BYT]

Warning: I'm a numpty with electrics. I have read various threads about towbar electrics and it all starts to go over my head with talk of 'can-bus', relays, reversing sensors etc. All I want to do is fit a tow bar to mount a bike carrier onto and then wire a towbar socket to accept a trailer board which is attached to the bikes on the bike rack. My car has 'bulb failure' indicators on the dashboard thingy. If I just splice into the loom for the towbar plug will all this stuff still work. I'm not worried at all about a dash warning light saying a trailer board bulb has blown and neither am i worried about reversing sensors beeping when in reverse and the bikes are mounted on the rack.
TIA

You cannot just tap into the system, due to the can-bus. What you can do is buy a socket kit which includes a relatively relay board which is 'can-bus friendly'. It basically draws a tiny amount of extra current from the existing lighting system, which triggers the relays. The relays then switch power to your socket for the trailer lighting board.

[hinged_bap]

You cannot just tap into the system, due to the can-bus. What you can do is buy a socket kit which includes a relatively relay board which is 'can-bus friendly'. It basically draws a tiny amount of extra current from the existing lighting system, which triggers the relays. The relays then switch power to your socket for the trailer lighting board.


ok, thx for that harry, can you help me understand this a little better, so one 'set' ( lets call them input wires ) of relay wires goes from the relay into the the existing loom, a hefty live wire goes into the relay from ????, ( where i know not ) , the output relay wires goes to the towbar socket, have i got that right. Other thing is what is a suitable relay to do this, would this be ok
http://cgi.ebay.co.uk/7-Way-Bypass-Relay-Towbar-Towing-Electrics-/270633362973?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3f0301661d

TIA

[Cpt Shed]

I've picked up a Towsure tow bar at the scrappies its almost new, it came with all the wiring attached including the very same relay that your link shows, I've yet to fit it though!!

Nige

[HarryM1BYT]

ok, thx for that harry, can you help me understand this a little better, so one 'set' ( lets call them input wires ) of relay wires goes from the relay into the the existing loom, a hefty live wire goes into the relay from ????, ( where i know not ) , the output relay wires goes to the towbar socket, have i got that right. Other thing is what is a suitable relay to do this, would this be ok
http://cgi.ebay.co.uk/7-Way-Bypass-Relay-Towbar-Towing-Electrics-/270633362973?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3f0301661d

TIA

That looks like it should do the job, but never having bought one....

I've only needed to fit the standard type (just tap into the wiring) on previous cars. When I bought the 75, I bought the full can-bus adaptor system and installed that - I thought it worth the extra for the fact it tells you about a trailer lighting fault.

I would assume the large wire or wires, need to be taken to the front to be fed from the left and right side main lighting fuse(s).

[hinged_bap]

That looks like it should do the job, but never having bought one....

I've only needed to fit the standard type (just tap into the wiring) on previous cars. When I bought the 75, I bought the full can-bus adaptor system and installed that - I thought it worth the extra for the fact it tells you about a trailer lighting fault.

I would assume the large wire or wires, need to be taken to the front to be fed from the left and right side main lighting fuse(s).

OK, thx, one last Q ( i think ) So do the 'input wires' on the relay have to go all the way back to the Fusebox ??, ugh, what a job that'll be, where/how on earth do i route them, is it carpets up time. Fitting the towbar seems a cinch compared to the job of wiring it up.

[HarryM1BYT]

OK, thx, one last Q ( i think ) So do the 'input wires' on the relay have to go all the way back to the Fusebox ??, ugh, what a job that'll be, where/how on earth do i route them, is it carpets up time. Fitting the towbar seems a cinch compared to the job of wiring it up.

I'm only suggesting the wires MIGHT need to go all the way to the front, your relay system is not the same as the one I installed. It is not difficult at all to get cables front to back, one of the easiest cars I have come across next to the SAAB I used to have.

Fitting the tow bar is a cinch on this car, assuming the bumper bolts are not seized. It just bolts straight into place, instead of the alloy crash unit thingummy panel. It really was the easiest one I have ever put on any of my cars.

[COLVERT]

OK, thx, one last Q ( i think ) So do the 'input wires' on the relay have to go all the way back to the Fusebox ??, ugh, what a job that'll be, where/how on earth do i route them, is it carpets up time. Fitting the towbar seems a cinch compared to the job of wiring it up.

The ONLY wire from the front is the power supply. :D