Thread: How bad can tradesmen get?

As many of you know, I work in the auto electrical field, but I specialise in dual battery systems.

In the last month I have had three situations I had to get involved in in which auto electrician’s work, to say the least, was appalling.

The first event occurred when one of my suppliers ask if I could look at a motor home, which had just been fitted with on of the supplier’s DC/DC units.

The motor home was based on a Toyota Coaster. These are 24v vehicles and this one had just recently been purchased by the current owners and they had had a problem where there fridge was only operating for around 6 hours before their house battery went flat.

they had done some research on the net and found that there motor home was fitted with a 24v to 12v step-down power supply and from their research, they realised this was not intended to charge the 12v house battery from the vehicle’s 24v system.

So they purchased a 40 amp 24v to 12v Sterling battery to battery charger.

Not having any form of auto electrical experience, the owner got an auto electrician to wire the new DC/DC unit and at the same time, they replaced to old 100Ah battery with two new 100Ah batteries.

the auto electrician wire the new batteries back to the DC/DC unit, and run a parallel circuit to their 3 way fridge, with both circuits fuse protected with standard in-line blade fuse holders. ( more on this later ).

With the “EXPERT” work done, they set off on a trip from Newcastle to Brisbane, stopping overnight at different locations alone the way and by the second night they found their fridge was still only running for around 6 hours.

So they contacted the supplier of the Sterling unit and explained they predicament, and the supplier suggests that they find a local auto electrician and get him to inspect their system.

This they do and the auto electrician finds that the previous auto electrician had fitted the two new batteries and earthed each battery to the vehicle chassis. So far so good.

He had then wired one of the batteries positive terminals back to the Sterling unit, via the in-line fuse, BUT, he had not connected the second battery’s positive terminal to the first battery’s positive terminal.

So these poor soles still only had the use of one battery.

The new auto electrician states that he will join the two batteries together but he must use a fuse to do this as it is illegal to join two batteries together without a fuse????????????????????????????????

So he joins the two batteries together using a short length of cable with a 60 amp in-line mega fuse fitted.

And that’s his “EXPERT” job done.

For a starter, there is no such law requiring the batteries to be joined via a fuse. Don’t have any idea where that one came from.

But worse still, there is a 40 battery charger ( DC/DC unit ) connected to these two batteries via a standard in-line blade fuse holder.

If this second “EXPERT” knew anything about the field he is working in, he would be aware that the highest rated standard blade fuse available is 40 amps, so at best, the fuse protecting this set up is a 40 amp fuse.

The problem is that while there are 35 and 40 standard blade fuses, they are not readily available and the largest commonly available standard blade fuse is 30 amps.

The second “EXPERT” should have known this. Both of the “EXPERTS” should also have known that you need to use both cabling capable of carrying much higher currents than the a circuits maximum expected current load and a fuse at least 25% larger than the circuits maximum expected current load.

In this case with a 40 amp charger, the fuse should have been at least 50 amps.

The save grace for both idiots is that the DC/DC device was also powering a 9 amp drawing 3 way fridge. So the fridge was just drawing enough to stop the battery’s fuse from blowing but it still could have got so hot that it melted.

I replaced the 60 amp mega fuse and lead with a short length of 6B&S cable between the two battery positives and then replaced the 30 blade fuse and holder with the 60 amp mega fuse and it’s holder.

Why the hell do the auto electrician not do this?

I then instructed the owners on how 3 way fridges must not be run off the house batteries for more than a very short time. Preferably not much longer than 30 to 60 minutes after the motor is turned and that if the stop is any longer, they need to switch the fridge to gas.

The two “EXPERTS” should have given this operating info.

“EXPERT” number 3

A couple of days ago, I have someone with a new D4 contact me to but a D4 battery tray and while this is all he needs, we get talking.

He is getting a new caravan and has been advised that he needs to fit a DC/DC device in the caravan, as the D4 will not charge the house battery while he driving. Not so but that’s another story!

He tells me the auto electrician has already installed a Redarc isolator in the engine bay and had wired up his D4 to be able to power the DC/DC device to be fitted in his caravan.

This wasn’t sounding to promising as there is no need to fit the isolator as the DC/DC device is it’s own isolator.

Anyway long story short, he was not sure what size cable had been used so got him to send me a few photos of the setup.

Sure enough, the “EXPERT” had wired up the D4 with the auto electricians favourite cable, 6mm AUTO, which is only 4.5mm2, while the correct size cable to use is 6B&S ( 13.5mm2 )

This guy is now going o have to start all over again.


Now to “EXPERT” number 4 and by far the worst setup.

Yesterday I get a call from a company on the NSW North Coast, which I have been supplying my gear to for more than 20 years.

They had a gent come in and wanted to know if they could fit a DC/DC device in his soon to be picked up new caravan.

The gent had a new D4 and the owner of the company explained to him that they always fit my isolators in the D3 and D4 and now DC/DC device was needed.

But he had been instructed by an auto electrician in Sydney, that because his tow vehicle was a D4, he had to have a DC/DC device fitted in the caravan or the house batteries would never charge.

The boss suggested the D4 owner give me a call and he did.

We had a long chat but the gent pointed out he did not have the slightest wiring knowledge but again, from what he told me about his setup, things didn’t sound right.

So I told him the best thing to do was to go back to the company and get them to inspect the set up.

This afternoon I get another call from the boss and he has a problem.

He did not want to touch the D4, and he explains why.

While trying to figure out what the auto electrician in Sydney had done, they gave him a call.

To their horror, he explains that he has run a single length of red ( positive ) 6mm2 cable from the rear of the vehicle to up under the dash on the passenger side.

But as he could not find a way though the firewall and into the engine bay, he had joined the cable to the D4's existing wire loom under the dash.

But wait, it gets worse!

The same “EXPERT” also fitted and wired up the D4’s electric trailer brakes.

He had done this by connecting the brake controller, under the dash to the cranking battery, via a 30 amp auto resetting circuit breaker.

So far sounds OK, but not so.

He has run a length of 5mm AUTO twin from the controller to the circuit breaker fitted near the battery.

This would normally be a length of 6mm AUTO cable, which is 4.5mm2 but as the twin 5mm AUTO means the combined cable size is 5mm2, so that's fine.

But what is anything but fine is that the “EXPERT” has then used a short length of 1mm2 WIRE to connect the circuit breaker to the cranking battery.

The boss told me they really didn’t want to touch the D4 and I told them that problem is easy to fix. I made it quite clear that I would not warranty any of my products if they were fitted to this D4.

This gent is literally driving a fire hazard and I would bet his warranty is now null and void, and all because he went to what he thought was an EXPERT.

This is what goes on in my industry. Is it the same in other automotive fields?

And then there was the bloke who got his mate at a suburban garage give him a hand to fit a gas system to his old Cruiser. They worked out that there was "room" for two cylinders of a 3 cylinder manifold tank to fit under the middle. So they acquired a 3 cylinder tank assembly, cut off one cylinder and even found a welder to weld plates over the holes. The bodged tank was then mounted with a few bits of inch by eighth angle and little more than gutter bolts. I received a phone call from the garage owner asking me to certify the system, as they had dun such a ripper job.

Come the day the owner appeared with the Cruiser, and he couldn't understand why I was sooo upset. An A4 sheet wouldn't have been big enough to list all the faults. Sent him off with a flea in his ear, I suppose it's still trundling around out there with a bomb hanging under it.

That's just the worst one, plenty of really bad gas conversions out there, some fitted by supposed "licenced" trained experts.