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Fitting towbar electrics

35K views 102 replies 21 participants last post by  haakon 
#1 · (Edited)
Edit
This thread started with my enquiries regarding wiring towbar lighting to the car but moved on to a detailed description of choosing and installing a towbar at post #16



I have fitted towbars to all my Alfas and just clipped the socket wires to corresponding wires in the rear of the car. I just run it to a lighting strip and have no need for a power link for a fridge etc.

This car has parking sensors so perhaps I need a bespoke wiring kit so that the sensors are deactivated when towing. Has anyone any experience of this? Are such kits just plugged into a nice socket already in the boot area? Can anyone tell me where to get one, without bothering a main agent?!!

The main agent I asked said that reprogramming of the car was not needed. He told me the price of his complete towbar and kit and I'm still laughing!
 
#2 ·
I'd also be interested in this - I'll be fitting a removable towbar to the Guilietta when I get mine. Whiskeymac - did you fit it yourself or go to a stealer to do it? You go for a removable one or fixed?

I've fitted towbars to other cars before and there really wasn't much to it, wondering if the G would be the same?
 
#3 · (Edited)
Guys, my wife is changing her 147 to a Guilietta and I too am interested in the subject. We had a Bosal Ecofit towbar fitted by an independent towbar supplier to the 147 and this was an excellent solution. The hook can be fitted and removed easily for towing but leaving just a small protrusion when not in use. Supply and fit was £459 and the towbar was specific for the 147. Although I am reluctant to fit a towbar to the new vehicle we do find it very useful to be able to attach a trailer.
 
#4 ·
Well I was hoping to find someone who had fitted one to a Giulietta but now I'm being asked for advice!! I have done some Googling and was very impressed by Towequipe. I spoke to their technical number where I was given excellent information and offer of tech help later if required. Westfalia do an excellent looking detchable which would seem to conceal the bar and socket when the ball is detached. It comes with electrics (wiring) which is a 7pin socket suitable for lighting strips. This is a "universal" set, which means just wires that are connected to vehicle wiring using clip blocks. Westfalia also do a 13 pin, vehicle specific kit which cost over 100 quids and needs a further converter for use with a 7 pin. The 13 pin system is what is used these days for transferring power to caravans; 7 pin is fine for lighting strips. Witter don't offer wiring. Towequipe also recommend fitting a bypass relay. Their code to search their site is TF 221, which actually lists 2 relays so I'll need to check which is the right one, hopefully the more discounted one. I pick up the car on Fri 19 Aug so will make sure I actually have it before ordering from Towequipe. Seems to make sense!! BTW, the description says that no bumper cutting is required. I'm going to attempt to get the stealers to give advice but am not holding my breath, though another towbar outlet (all seem to be very helpful people) gave me the number of an Alfa agent who is very helpful with such advice, so I envisage a call there too.
 
#7 ·
Why don't cars come with the lighting port in the boot ready to go? Sounds like with ESP and PDC these are getting harder to fit. So much easier if they came pre-wired then just extension cable out of the boot.

I want a light board for my bike rack, but don't want a towbar or the expense of fitting one.
 
#8 ·
The towbar is fitted, thanks to the spell of dry weather, and I photographed the processes. I need to process the photos to lower res before poting here with full description.

The current wet weather and commitments have delayed connecting the cable to the car's electrics, but I'm on the job. Because there is a bypass relay to be fitted between the two, to prevent fault signals, I need to connect it to a constant power source so that the 4 way flashers work with the ignition off. For a simple trailer, the only light connections needed are right and left indicators and rear lights and the brake. All looks straight forward except that the brake lights and rear lights are the same LEDs and seem to share the same wire at the light plug. (The LEDS just go brighter when the brake is applied as a result of a higher current it would appear). So how do I connect separate leads from the bypass relay?

Any ideas out there?

I think I'll have to consult an Alfa fitter on this one.
 
#9 ·
Thanks for the update Whiskeymac. I am still interested in this. It never occured to me that there would be an issue with the LED side/brake lights but I can understand the problem. There must be a solution as these are becoming much more common. Please keep us posted on your progress.
 
#10 ·
It's looking hopeful. I'm very impressed by the sevicing department at Meridian Modena in Bournemouth. They are very willing to pass on such info and have offered again, but the fitter who has fitted towbars to Gs is away until Monday. He was very helpful answering questions on this subject when I collected the car, giving me the confidence to undertake the job. Best bit of advice was to allow two days to do it!
 
#11 ·
Well that went well!!

The Meridian fitter uses the Alfa towbar wiring harness which just plugs into the lights somehow, but at a cost of £190.51p I'm not about to find out either!

I phoned the towbar supplier, PF Jones, and, without expecting success, asked how I separate brake and tail lights for the towbar wiring. Immediate answer: you only connect the red wire from the bypass relay (supplied) and the relay sorts it all out! Brilliant.

Since I'm only wiring for a simple boat trailer, it would appear that I only have to connect three wires from the bypass relay (rt and lt indicators and brake/tail lights), plus set up a relay power lead and earth. Can it be so simple? More in due course, weather and bad back dependent!
 
#14 ·
Sounds like its a bit late for this advice, but I really would go for the 13 pin socket. The sockets are far superior mechanically and electrically, and its the new standard for everything going forward. Adapters are cheap.
 
#15 ·
I have 3 trailers and don't like adapters. I'd also have to change the system on my motorhome and that would be a very difficult bumper off task. Anyway, an adapter would be yet another thing to go missing just as I'm ready to set off. No problems with mechanics in 40 years so I'll stick thanks.
 
#16 · (Edited)
Fitting a towbar and associated electrics

FITTING A TOWBAR AND ASSOCIATED ELECTRICS

Ok then, this is how I fitted my towbar and electrics.

Note that you can click on any photo to see an enlargement in a separate window.

First find your product. If I tell you that the wiring alone for the Alfa supplied one is about £175 (£193 from local agent), you can perhaps guess that there are cheaper products around, though the wiring is a plugin apparently. Oh yes on line towbar price, minus electrics £485 (yes really - I've back checked 3 times!).

I chose P F Jones as my supplier and this product:

Alfa Romeo Giulietta 2010 Onwards Westfalia Detachable Towbar

I can't express how satisfied I am with the guys at this firm. Prompt delivery, charges low and immediate, detailed responses to any questions asked regarding fitting.

You will need to decide what connector plug you want to use and order accordingly, including the relay. I used the 7 pin standard as that is what is on my motorhome and all trailers. By all means use the 13 pin if you wish. I see that I've written elsewhere that this is over a hundred quid.

This Westfalia detachable towbar is completely invisible when looking at the rear of the car. The electrical socket is swung down when required and the heavy swan necked towball is attached very easily, clicking into a holder from below. When not required the ball assembly is stored in a plastic bag.


Arrival

The product arrived in a big log box with masses of padding. It weighed a worrying amount but once unpacked, so did the discarded packing. Have something soft at hand to place the towbar on when unpacking so as not to scratch off the paint on your driveway. The assembly looked really good but I gave it a couple of coats of spray on black Hammerite just for good measure, even though I knew it would be mostly out of site.

Preparation

This job is going to take you at least 2 days unless you've been fitting towbars all your life, so if you propose to do it out of doors, make sure you choose good weather. Possibly wait until Spring now! Or find an indoor facility. (The local Alfa fitter said he allows 2 days).

I haven't listed all the tools required although mentioning some for clarity. I suggest anyone undertaking this task should read through and make sure that the tools mentioned are available at the outset. Some form of bright lighting will be essential for marking and drilling the towbar attachment holes. A torque wrench should be used for safety and if not owned, can be borrowed for the few minutes necessary to tighten the 9 retaining nuts and bolts. Should the lighting strip lights not work after wires are connected, a test meter will be invaluable to trace where along the line there is a power break.

Rear bumper removal

This was a bit daunting but I hope to help remove your daunt.

First remove 3 cross headed screws in the rear of the rear wheel arches, and a 30T star head bolt at the top rear. If you jack up each side in turn and use a very short screwdriver, you don't have to remove the wheels. Store all removed screws and bolts safely where they won't get lost.

Unbolt the single bolt holding each rear light cluster to the boot recess.

Remove the screws along the base of the bumper underside.

Place something like the top from a sun lounger on the deck for the bumper to land on.

Grab hold of the bumper by the wheel arch and pull outwards gently. You will be rewarded by a series of 3 pops as it detached from 3 mounts.

Now, at this point the handbook just says to pull. Pulling worked; there was a forth pop and it all came away rather alarmingly. A better way would be to remove the light cluster first, using the patented Whiskeymac tool, a polythene spatula, the type that melts in the frying pan! (Thus not the hard plastic type). This can be inserted under the edge of the cluster at the bumper edge to pop off the cluster as shown in the photo. This is good practice for changing bulbs in years to come.
The technique is described here:
http://www.alfaowner.com/Forum/alfa-giulietta/309643-rear-light-cluster-removal.html

The following photos, will explain the reason for the problem. One shows the slots on the bumper that popped (the end smaller slot is where the 30T bolt went through). It also shows two further slots ( top on photo) that mesh with the light cluster. The second photo shows the two protrusions at the bottom of the cluster, that do the meshing.

Automotive exterior Bumper Vehicle
Auto part Vehicle Trunk Automotive exterior Car


So if you removed the lights first, the bumper can be popped off and gently placed on the soft sun lounger top, or whatever, below. Unplug the lead for the number plate lights and, if you have them, the reversing sensors. The next photo shows the removed bumper which, being entirely made of thin plastic, incidentally is extremely light weight. Place safely aside.

Vehicle door Automotive exterior Bumper Vehicle


Remove Plastic Bumper Undersection

Undo the six nuts holding on the undersection shown in this photo and discard the undersection. It isn't needed anymore.

Bumper Automotive exterior Auto part Subcompact car


Drill attachment holes

For the purpose of understanding the next stage, the towbar may be placed temporarily onto the six bolts, sliding the two flat arms inside the corresponding box sections. The arms have threaded holes. Corresponding holes now have to be very precisely drilled through the underside of the box sections.

First remove the towbar. Study the supplied templates. They have small car pictures to assist identifying which is left and right and their orientation front and rear. You will need a short metric ruler or devise some other way of transfering measurements. Mark with a pencil, double check, go away and have a cuppa, return and measure again, carefully. Measure twice (at least), drill once!

When you are absolutely certain that you are going to drill in the correct place, first unbolt the rear exhaust pipe mountings. Decide which side is to be drilled first and use a couple of bungees to pull the exhaust away from your drilling line. Also remove the square rubber plugs in the box sections and note that the one on the off side of the vehicle is where one bolt will go, i.e. you only have three holes to drill.

Make sure your drill batteries are fully charged, if using battery power.

The 18mm holes you need to make are larger than the largest drill bit you are likely to own, so get equipped before starting. It is also larger than is necessary for the bolts supplied, but allows for a bit of error. For those not used to drilling large holes through steel, you cannot use large drill bits straight off. Punch a start mark if you can, or use a tiny drill bit to drill a shallow pilot hole, then change to gradually larger bits, drilling right through with each in turn. A slow speed actually penetrates faster.

When all holes are drilled, check alignment by fitting the towbar and holding your breath. If all is well :thumbs: you can clean up the holes and treat with rust preventer, though I used dollops of grease. Fit washers to bolts and wind them in halfway until certain that all fit fine, then tighten up with a torque wrench to the torques given in the instruction diagrams. Fit washers and nuts on the rear bolts and tighten to their lesser torques.

Should you have been a bit ham fisted, you can always enlarge one side of a hole with a rat's tail file. If you have been completely ham fisted, buy another car and start again.

Take the plastic electric socket mounting from its packet and assemble on the bearing as shown on the diagram in the packet, and mount on the drop arm of the towbar. Your car should now look like this:

Vehicle Car Bumper Automotive exterior Exhaust system


Cut out section from bumper underside :wow:

The section to be removed is shown in diagram 12 of the instructions. It is larger than you would expect, but is necessary to accommodate the ball bar locking mechanism handwheel and allow your hand to operate it. Don't fret, it is completely invisible from the rear of the car. It is quite tricky to measure and mark, I found, due to the curves of the bumper.

This is a good time to familiarise yourelf with the towball setup and try to understand the instructions on pages 26-27. I found it easier to fiddle with the ball assembly, fit it, lock it, then worry about how to get it off again. Once you've got it to lock on you've just about cracked it. Just read the 'structions again for good measure. No I still couldn't follow them either! Seeing it fitted will help you understand why the section has to be sawn out of the bumper.

Once the markings are pencilled on, another cuppa consumed then the markings and measurements again checked with great care, start cutting. I used a fret saw for the depth cuts and a very carefully applied Stanley knife for the cross cuts. By carefully, I mean very gently against a firmly held ruler for the first cut, then gradually deepening the cut, resisting any attempt to rush. Once complete, remove sharp edges and corners with abrasive paper. By all means use a power jigsaw if you prefer. They scare me more than a Stanley knife. There may well be other methods.

Mount Electric Socket

Mount the socket on the plastic swing mount, using all supplied washers and applying a little grease, silicon if you have some. Note that the cable snags a bumper mount. I slid a length of water pipe that I had, over the cable, to give protection at this point. It's not going to be used every day, but I feel better to have protected it.

Make a hole in the large rubber grommet that the cables go though into the bootspace; pass the towing cable through and seal with some sealant, mastic etc. I used some black silicon.

Refit Bumper

Refit the exhaust mounts if not done already and give your exhaust outlets a good clean.

Place the bumper behind the car and replug the numberplate light and reversing sensor cables, feeding them logically so they won't get crushed.

Offer up the bumper ensuring correct meshing with the fittings just beneath the boot opening. Ensure the rubber seal is fitted correctly. Rescrew and bolt and check there are no leftovers or missing bits :rolleyes:.
This is a good time to go and open a bottle of vino and celebrate.
The damned electrics can wait until you feel like tackling the job. Fortunately it's easy, thanks to the Whiskeymac instructions below, aided by those grand chaps at P F Jones.:cheese:
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Connecting cable to car wiring

The towbar connecting socket cable was, by agreement, sent with a bypass relay. This serves a number of functions including prevention of voltage drops being reported as faults, providing a mandatory bleeper to confirm working of trailer indicators and resolvement of the LED conundrum (see later).

First you need to know how the socket and relay are wired. This info does not come supplied!! I'll list the details here and the vehicle wires that I connected to. If you want more than indicators, brake lights, side lights (including number plate lights), you will have to delve deeper for the corresponding vehicle wires.


[Tabs and multi spaces are not supported so dots have been used here instead to create columns]



Connect the towbar cable wires to the relay connections first.

Towbar socket to bypass relay numbered terminals:

1…….Yellow
2…….Blue
THERE IS NO No 3
4…….Green
5…….Brown
6…….Red
7…….Black

The white wire goes directly to chassis earth, along with the one from the bypass relay.



Bypass Relay wires......Function..............Connect to car wire colour


Green (extended).........Right Indicator…….Blue/Black lead to right rear light cluster
Red…………..................Brake……………..…...Red/Yellow to LEDs in left rear light cluster
Yellow………................Left Indicator………..Blue/White lead to left rear light cluster
Blue………….................Fog
Grey………..................Unused (Reverse)
Brown……................…Right Tail…..………….No need to connect *
Black……….................Left Tail……..…………No need to connect *
White……................…Chassis earth….……To Chassis earth

* The tail LED lights double as tail and brake lights. Only the brake connection needs to be connected, the relay sorts out the tail light feed.


Connect Power to Relay

The relay needs to be connected to a constant power source (12v +) so that the emergency four way flashers work with the ignition off. There are two connecting screws on the side of the relay, connect to the one marked 12v. For power source see next section.

Locating Vehicle Wires

Most of the wires required were found on the rear nearside, behind the boot lining. To expose these procede as follows.

Undo the star headed bolt holding in the plastic boot rear lining and ease this upwards and inwards, peeling it out of the rear seal and lifting out of the mounting slots. Note these slots for when reinstalling.

Undo four cross headed screws in the assembly carrying the boot light, two in obvious recesses (use a torch), the third exposed by pushing the rear seat forwards and the forth by removing the triangular plastic surround of the seat back anchor post. The assembly can then be eased inwards, along with the lining outer trim and then the inner rubber lining. Without going mad, this creates enough space to work and access to the rear wiring loom. Locate where the wires enter the rear lights and find the left indicator wire and the left tail light wire.

Vehicle Car Car seat Car seat cover Vehicle door


Using one of the blue clips supplied attach the appropriate relay wire to the indicator wire. If you haven't used one of these clips before, here's my suggestion of how to do this. With a pair of pliers in one hand, find the rear channel in the clip that is blocked off, push in the relay wire, yellow in this case, and ensuring that the wire doesn't slip out, gently close the clip with the pliers just enough that the wire is trapped. Prise open the clip and, having exposed a length of the correct vehicle wire, blue & white in this case, slip it into the other channel and pinch the clip closed. Flip over the cover and snap into place.

My power wire was a nice fat red one in the loom cluster on the floor and can be seen in the photo. It was a bit of a struggle to clip it but I managed to prise the metal prong apart a bit so that it fitted. A short length of wire is required for the connection from this clip to the supplied fuse terminal (using a supplied blue female spade connector), and similarly from this to the 12v terminal on the relay. Subsequent people following this guide have reported that they failed to find a fat red wire. My advice would be to look for a big, fat black, or even blue wire as Alfa seem to have changed the colour on later cars. To be sure, use a voltmeter (test meter set to Voltage), touch the black probe to a good earth (The body of the vehicle negative pole) and stab through the insulation of the wire. If it is a permanent live you will get a 12v reading. Test meters are very useful for a myriad of other functions such as testing cable continuity, fuses and light bulbs, and all sorts of batteries. It is confusing to see a black wire and consider it to be a possible positive (+) source but from what I gather from others, this is the case. [In the event that no suitable power source can be located, a new cable fitted with an in-line fuse will have to be routed from the battery as described in Post 50. It might be expedient to route 2 cables should you have thoughts of fitting reversing sensors in the future].

Next, bare the ends of both white wires, from the cable and the relay and, having loosened the 13mm nut on the earthing post, slip in these earth wires and retighten.

Connect a lighting strip to the towbar socket and test that the left indicator works on the strip and the buzzer buzzes in the relay.

Using another length of wire and blue clip, extend the green wire so that connection can be made in similar fashion to the indicator wire on the right tail light assembly. I used a piece of two core indoor power cable for this, threading it through the back panel of the boot from high on one side to high on the other. Once complete, test the four way flashers without turning on the ignition.

At this point the conundrum appears. If, like me, you had used a test meter on the wires to the rear light cluster to establish which was which, you would realise that there seems to be a wire missing, as the LEDs double as tail lights and brake lights. A phone call to
P F Jones revealed that only one wire, the red brake one, needs to be connected, after which the relay sorts out what happens at the lighting strip from the power coming through the LED wire. Clever eh! Thus, on the left side, the red relay wire is connected to the red and yellow cable. No further connection is needed for either tail light. (If I was crass I could say simples at this stage, but I'm not, so I won't.

Well that's it! Just test that the tail and brake lights work on the lighting strip. I just tidied up the wiring with black tape, also taping the power clip cover shut which kept springing off, and taped the fuse holder so that it was accessible but so that it won't rattle around. Replace the linings, back cover and all screws and bolt and rejoice at how clever you are and how much dosh you have saved. :D
 
#21 ·
The pictures now work, sort of. The first one is there with the text, but the rest are only visible when their links are clicked. I've PMd for help. At least I certainly did send a message but am showing as not having sent any. So frustrating. I've spent hours on this. :rant:
 
#22 ·
Yeah the forum image handling is *very* clunky compared to other forums I use, I used to use images from the web but they stopped IMG code now I think apart from pics forum?

Your best to put your article on the internet somewhere and not add the content to alfaowner if you want proper inline images was my experience!
 
#24 ·
Thus it gets weirder. Yesterday all the rest of them came up in separate windows when clicked on, now I'm getting the same as you.

I've emailed the administrator but no reply yet. Can't seem to work out how to PM, but the email, if that's not a PM, hopefully will elicit a solution. I'm not giving up on this. Yet.
 
#25 ·
Well, at last I've succeeded in embedding all the photos. To do this it's absolutely essential to go to advanced editing from the outset and to go to the foot of the page (where I'd not looked...why would you!) and click on Attach Files to open a management window. From there you can browse for the files, upload them (maximum 6), then, returning to the edit window, drop them in amongst the text by clicking on the attachments icon and selecting the uploaded file.

Previously I had started with the attachments icon, which had opened the management window, then returned to the attachments icon and in went the link.

In both case the edited reply window looked the same, but only proceding in the sequence as first described, resulted in success. The second sequence just resulted in dead attachments.

Hope it was worthwhile fellow G Alfistis. At least I'm older and wiser!
 
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