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[Marks DTM Calib]

The install:



Crappy scotch locks, signs of where the wrong cable was selected to start, scotch locks used to extend a cable by 100mm, loads of tape, quite a mess.

The main power connection:



So how do you make your main power connection?, clearly in this case the preferred approach is to strip the insulation a bit and wrap your wire round it followed by a good dose of tape. This connection supplies the fridge electrics, charge for the leisure battery and the canbus lighting module so many tens of amps! (read potential fire risk).

What's worse is that this was carried out by a Witter approved installer as recommended by a main dealer......

The fix was to re-make all connections using solder and heat shrink (self amalgamating tape around the main power wires so as to avoid cutting them)and then loom tape around the wiring to make it a lot neater and hence more reliable.

[Auto Addict]

Brilliant job, thanks again Mark

[Marks DTM Calib]

Brilliant job, thanks again Mark

Not a problem, good to see you again 

[candyman]

The install:



Crappy scotch locks, signs of where the wrong cable was selected to start, scotch locks used to extend a cable by 100mm, loads of tape, quite a mess.

The main power connection:



So how do you make your main power connection?, clearly in this case the preferred approach is to strip the insulation a bit and wrap your wire round it followed by a good dose of tape. This connection supplies the fridge electrics, charge for the leisure battery and the canbus lighting module so many tens of amps! (read potential fire risk).

What's worse is that this was carried out by a Witter approved installer as recommended by a main dealer......

The fix was to re-make all connections using solder and heat shrink (self amalgamating tape around the main power wires so as to avoid cutting them)and then loom tape around the wiring to make it a lot neater and hence more reliable.

I see this type of work all the time. Its all done to a price. I am an electrician and when I say what I need to do the job they say its too much. 6 mths later they pay me to fix it again anyway. I also try not to solder wires as it fatigues the wires and usually breaks through time but that's mostly on trucks. Crimp connectors are just as good and recommended by a lot of manufactures. Phones and trackers are another sore point!

[Marks DTM Calib]

I don't buy the time story, it takes pretty much no longer to do a proper job  (this from an Elec/Electronic engineer leading designs on ship electrical systems). In fact, its arguable that its cheaper as you get far fewer returns (this install for instance had been returned once and the fridge relay replaced.....the true fault was the wiring and hence the cost of the relay and time to fit had already eroded the profit). 

Considering also that the install also presented a fire risk due to the I²R loss heating from the main power connection and that they had investigated a previous issue and failed to identify the route cause.

As for soldering fatigue, that's why its important to dress the wires correctly afterwards and of course, you can get the same with a crimp as it chafes on the edge of the crimped metal feral 

Interestingly, I am yet to see a set of manufacturers instructions saying to use scotch locks (they often show crimps which are fine as its a good gas tight joint) and all the Vx/Opel ones are freely available to download online.

[Gaffers]

I think that install is worthy of a call to trading standards, shocking workmanship and to think a fire hazard too

[candyman]

One of my customers fits towbars as part of his service and says there's no money and therefore time in them. He says its to cut throat but has to do it to keep his customers happy. He informs me most of the time there's only £20 -£30 clear profit from one job but to keep customers happy he does it ( he does van conversions) . He does solder and shrink the joints but he has already had problems with solder causing resistance in led lights and failure warnings coming on. They or myself do not use scotch locks anywhere.
 Daf recomend the crimp terminals for repairing looms etc, there is now crimp terminals aviable with heat shrink around them that are great. Many times I've had to fix chassis looms where's someone has tried to solder the joint and it hasn't set due to a bit of corrosion. Its all about getting the truck back on the road quickly with a good reliable repair, especially where brakes and canbus are involved.
 Also I've repaired a lot of soldered repairs on trucks and trailers where it has broken at the end of the solder. The constant vibration me thinks. Any other electricians who work on the same vehicles as me agree with this (we all help each other out with tech advice, me being daf trained).
That job is very bad I have to agree and I would complain and name and shame them. The dealer also needs to know.
 
 Sorry to highjack the thread!

[Kevin Wood]

Just like the standard of work you's expect from your average UKLPG muppets. 

The problem, in my view, is a failure to understand the possible consequences of such shoddy workmanship and / or a failure to give a sh1t.

If you don't understand why something is the way it is, you follow the instructions. If you have a good understanding of the discipline, then you can go off piste, but need to be qualified and prepared to argue your corner should it go horribly wrong.

Very few towbar installers are qualified electrical engineers, so they should be following the instructions to the letter.

I fail to understand why instances where the trades create electrical death traps are everywhere, yet ask anyone not qualified to work on a gas installation and they won't touch it. The potential to kill people or damage property is just the same.

[Andy B]

.... Many times I've had to fix chassis looms where's someone has tried to solder the joint and it hasn't set due to a bit of corrosion.  ....

that's the problem I had yesterday trying to fit a repair loom to the Smart. The wires in the original loom wre corroded & were a bugger to get the solder to flow on. 

[Marks DTM Calib]

But even using a crimp on corroded wires is going to cause issues as the basics are that the corrosion is increasing the joint resistance and your back to the good old I²R issue again

If someone is soldering something and does not have the basic knowledge to recognise that the joint is poor then there not good at soldering.

[candyman]

But what do you do? You have a chassis loom with 30 wires in it which is in a chassis leg, beside gearbox with a pto and a hyd oil tank and can't remove the loom completely unless you spend another day removing exhausts, turbos etc ( volvos are a prime case) to start to route new wires in which aren't the same colour or number? Once a wire has water ingress its always there unless you change the loom which is megabucks and downtime. Then you can't get enough loom out to fit the heat shrink far enough away that the heat from the solder doesn't shrink it. The new terminals with shrink round them are a godsend, tight enough due to crimping with a completely water tight connection. If they don't do then you admit defeat and look to replacing loom\looms. But 99% of the time there good enough and doesn't give any more issues provided the looms are routed securely and correctly and not left hanging chaffing on brackets etc, daf cf are prone beside cab ram with cab moving up and down and volvo fm\fh behind headlights are two prime candidates.

[Marks DTM Calib]

The key thing to do is re-wrap the loom with suitable tape afterwards to ensure the crimped (or soldered, shame its hard to get Rosin flux cored solder these days!) is suitably supported to remove the loads on the joint. 

[05omegav6]

Surely if the same bits of loom are failing in the same way all repeatedly then there is either a fault with the oiriginal loom or the subsequent repair

By your own admission, you are ultimately replacing sections of loom with new, because the repair hasn't taken...

Surely it's quicker to replace with new from the get go and secure it properly to prevent chafing, than to mess about trying to botch it back together, only to have to go back to it later... if Volvo/Daf/Paccar are actually made aware or repeated failure of the same loom in the same places of various models, then perhaps they might do summat about it, by upgrading or rerouting the loom for instance 

Looking at those pics though, I suddenly feel alot happier about my wiring...

[omega3000]

What's worse is that this was carried out by a Witter approved installer

 

Looks like a 5 year old tried to wire that previously  Whats the thought on the wiring blocks for connections , the type that you screw down onto the wiring .. surly better than twisting 2 bits of wire together and hoping they stay together 

[Marks DTM Calib]

Depends on the type of block, many are a screw which clamps the wire as you wind it in (on better ones, the screw acts against a metal plate), trouble is they also cut the wire as you turn them!

Much better to solder or use a crimp. 

When we make connections to screw clamp setups we fit a crimped narrow blade on the end and then clamp to the blade ala: