towbar electrics

[Wideboy]

Fitted a removable tobar to my 3 series Tuesday night and planned on hooking up the electrics this evening but I was wondering if someone more clued up in electrics could answer me something.

I have a 7 pin single plug as I shall be only towing a trailer so I only need to operate lights ect. my intention was to tap into the electrics on the back of the car... I.e. trailer drivers side brake light into the cars drivers side brake light ect... you get the jist.

Whilst looking up on Google people on different forums are saying stuff about needing a relay or a bmw towing module. I was under the impression a relay was only needed if you were towing a caravan ect to operate fridge and charge the battery ect.

Also have my buzzer to wire in for the indicators

What will happen if I just tap into the lights on the back of the car?

Love from Gav, confused in southampton.

Hi,
it's been a while since i done a towbar, but i think you will need a replacment relay for the indicatores as the output will be higher as you are adding on another lamp so the realy can flick on and off at the correct speed.

you can normaly get a loom that has the appropriate multi plug to tap in without having to cut the wires in the car (well you do for the 4X4s i worked on).

[Wideboy]

Yeah you can but they're 116 quid for BMW's :s hence just buying a generic plugless one

I did think the indicator speed would be off. Apparently this whole module business something to do with the cars computer being able to tell you when you have a bulb out, something that I'm not interested in.


this is all a bit of a bummer I was hoping to use it this weekend

[NTECUK]

Allot of modern cars use "can bus" to monitor the bulbs.
Its theses cars that need a module .
BMW are one such manufacture that use this system.

[Wideboy]

Fook it so I need a module?

I think my flashed buzzer is also a relay but not sure

[Wideboy]

Yes i need a bypass relay bugger

Thanks anyways

[Wideboy]

One of these should do it?

http://www.towsure.com/product/Smart_7_Way_CanBus_Relay

[NTECUK]

Yes Thats the kido
.Solder the wiers as well sotch locks cut the loom conductors

[Wideboy]

Well the org has solved a problem in a hour, what's taken about 3 of Google searching

I think I saw one in there when I was getting the flasher buzzer last night so I'll go and purchase one on the way home.

Thank you muchly x

[Wideboy]

what a fooking balls up!!

purchased said relay on my way home from work, arrived home just after 5 and opned the packet to begin fitting. First things first INSTRUCTIONS! reading it the relay needs to be connected to the battery with an inline fuse and earthed.... not a problem, its a bmw the battery is in the boot, hunting through the box there is no in-line fuse or wire provided, so it now being about half 5 off i go to halfrauds to be ripped off. Get home to continue with the job... oh no wait the wires coming out the relay aren't long enough to tap into the passenger side lamps. so i gave up and proceeded to hunt out which wires i needed on the loom with a needle and multimetre (i have no wiring diagram).

so pretty much got feck all done this evening, did watch an epic thunderstorm though in-between swearing. back to it tomorrow

back at it tomorrow night