My towbar fitting notes (2.5V6 2000 facelift estate).
Part 1
General info
The round socket that you have in the boot area will supply all you need to wire up your 12N socket including a large red wire that's intended to supply 12 volts to your caravan for lighting, charging & fridge (the 12S socket). On the estate the plug is hidden up behind the jack.
The rear fog circuit is looped through the towing connector via 2 pins that short when the plug is removed. The idea is that the towing connector switches out the vehicle's fog light when the trailer plug is inserted.
No need for bypass relay kit.
There’s a big grommet in the boot floor to drill and feed the wires through.
The dash Trailer turn signal is the picture of a tow hook just below the 0 on the rev counter. The symbol indicator flashes in time with turn signal lamps when towing. It does not flash if a turn signal lamp on the towing vehicle or trailer fails.
Towballs – if towing a modern caravan it’s likely have an Alko stabliser. Standard tow balls aren’t suitable, you just need to spend a tiny bit more and get one that’s suitable. Not A50-1, must be EC94/20 A50-X or Swan neck.
http://www.al-ko.co.uk/automotive-towballs.htmhttp://www.al-ko.co.uk/edit/files/support/Towballguide.pdfTowbar fitting tips:
1) If you have to remove the tar-like insulation / sound deadening material from the boot floor, heat it up with a hot air paint stripper to soften it and then scrape it away with a decorator's chisel. Only remove the areas that the towbar will sit on. It's easy to remove when hot and impossible when cold.
2) When drilling the holes in the floorpan (you'll find these pre-drilled and covered with a thinner metal skin) use a smaller drill bit than specified at first and work your way up. You probably won't need as big a hole as specified in the instructions because they seem to be catering for a certain amount of ham-fistedness in locating them!
3) De-burr and paint all holes in bodywork / floorpan with Hammerite. A spray of Waxoyl on these areas once dry won't hurt either. A touch up pot is ideal.
4) Any securing bolt that passes through a chassis box section (just behind the diff on a saloon, for example) MUST have a spacer fitted to prevent it crushing the box section.
5) Check all fastenings are at the correct torque after first use.
6) If you buy a Witter towbar one spacer is specified as M12 x 40 x 4 this is what you need. In the kit is a M12 x 40 x 2. If you fit this it will rattle really badly. Contact Witter and ask for the right part. They sent me another wrong part! But put them together and you should be fine.
To do
• Fit fuse for 12V 12S feed.
On some cars it’s fuse No29, in the panel under steering wheel.
On the 2.6V6 and 3.2V6 it’s fuse 5 (30A) for the tow bar constant feed.
On my facelift 2.5V6 it’s fuse 5.
Fit Trailer Brake Bulb Failure Sensor (looks like a relay) that lives behind the glove box (on Facelift). It's on a metal bracket to the left hand side of the glove compartment up under the passenger side of the dash. Difficult to access, you will have to remove the heater vent and glove compartment to find it. It’s then hidden above two other relays (red and grey).
Without it you have no brake light feed on the trailer connector. You can just link this across: then you get brake lights but without bulb monitoring. It's a 4 pin base (P39 on wiring diagram) of which 2 pins need bridging (pins 2 and 6 - make up a 2" length of wire with a spade connector on each end and it'll do the job). The colour coding of the two wires that need bridging are the same as the colour coding of the brake light signal at the towing connector (black and yellow) (and the two wires are the same colour code) so they're easy to spot. The other two wires on the socket are not coded the same and should be left unconnected.
Part number for correct part: 90463123. Costs £15.55 + VAT retail from Vauxhall. Part not used for anything else, only trailer bulb warning sensor. It’s used in Astra-G, Zafira and Vecta B and Omega B. It’s a special order from Germany and will take 7-10 days to arrive.
• Indicator relay. Swap your 3 pin relay for a 4 pin one rated for 6 indicator bulbs with bulb failure sensing. It’s the central one in the cabin relay box under the steering wheel.
GM part number “Flasher 2/6 x 21W” for trailer 90506697 £30.55 + VAT retail
This £5 “Merit Malta” one promises to do the job but doesn’t quite work correctly (the tow indicator glows a bit when the trailer is not connected). It also has quite a leisurely flash!
http://cgi.ebay.co.uk/Flasher-Unit-12V-4-Pin-126-Watt-Trailer-Towing_W0QQitemZ130232402419QQcmdZViewItem?_trksid=p3286.m20.l1116Intermotor catalogue part no: 58940 from my local Motor Factors £13.00 + VAT should be the right part (but I didn’t get it to check)
So bought this one, “12V Nagares Flasher Hazard Relay Unit Caravan Trailer”
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=280274707853&ssPageName=ADME:B:EOIBSA:UK:11Works fine, cost £13
• Put a lamp in the dash where the towball telltale is. The bulb should be 12V 1.1W (but 1.2W seems fine).
http://www.omegaowners.com/forum/YaBB.pl?num=1152618876http://www.omegaowners.com/forum/YaBB.pl?num=1192573381http://images.omegaowners.com/images/guides/How_to_Remove_Clocks_Panel/dashremove.html• Deal with fog lamp deactivation contacts in towbar connector:
a) Leave the socket in place and pins remain shorted so the car fog lights continue to work (as well as the trailer)
b) Or buy a 12N socket with fog light switch built in (Ring do them, RSA495 or RSA490)
In theory the complete wiring kit for a 12N socket is available from Vx (12N socket, flasher relay, dash bulb, bulb sensor unit and cable assembly with mating connector for the one in boot) but it seems demand was low and they’ve discontinued it. Part no was 9193983 but number not recognised.
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Topic: Fitting tow bar (Read 3102 times)