Tech Talk

Help on Falcon towing
Keith Cassidy from Harden, NSW, sent in some comments that may help Bruce Fuller who queried the amount that could be towed with a Ford Falcon.

Keith tows a 16ft 5in (5m) Jayco with a 2005 Falcon and in January went on a trip down the NSW coast to Narooma. Over a distance of 339km he averaged 19.2 L/100km (or 14.7 mpg).

On the return journey through Bateman’s Bay and up Clyde Mountain, Keith says that the consumption was higher. The Falcon engine overheated while climbing the mountain, bringing on the temperature warning light.

As Keith had nowhere to stop he kept going. At the top the temperature gauge dropped quickly to normal. He concluded that under the circumstances he was glad that he had not been towing a heavier 6m van.

On the type of journey undertaken by Keith, consumption is never going to be great.

Good fuel consumption can only be achieved on long flat stretches where a steady cruising speed can be maintained.

As Keith found, it isn’t until you climb a steep mountain that you realise what effect a tonne and a half of trailer has on available engine power.

Everything considered, Keith was probably fortunate that there wasn’t anywhere to pull over when the engine temperature went up.

A lot of damage can be done when a hot engine is switched off and any cooling that may exist suddenly ceases.

It is often better to keep going at reduced speed so that air still flows through the radiator core and the water pump continues to circulate the coolant.

This wouldn’t apply, however, if there had been a drastic coolant loss.

To cool an overheated engine that hasn’t lost coolant, stop the car, keep the engine idling and pour cold water slowly over the front of the radiator.

The fan will pull the water through the core and quickly reduce the coolant temperature.

Of course, never remove a radiator pressure cap until the engine has cooled down, which can take a considerable amount of time.

Help with turning off lights
Bruce and Bev Reeves’ problem with the glare from the car’s reversing light bouncing off the front of the caravan (April 06 Caravan Clinic) struck a chord with Rod Hanger from Bargo in NSW.

Rod had a similar problem but he also found a solution. Rod made two modifications. First, he fitted a 12-pin plug in place of normal 7-pin one as more terminals were needed (see diagram).

This enabled him to fit reversing lights on the rear of his van. Narva lights were used which were wired to the front of the van through protective tubing fixed to the chassis.

Second, Rod fitted a 5-terminal normally closed relay to the reversing lights circuit of the car. When reverse is selected, the relay prevents the car’s reversing lights coming on but allows the ones on the rear of the van to show the way behind.

The relay is ‘switched’ by a bridge that is installed in the 12-pin plug on the van. This bridge is connected from the ‘hot wire’, that goes from the car’s battery to the caravan interior, to an adjacent terminal.

When the 12-pin plug and socket is joined together, power from the ‘hot wire’ is sent to the relay. This in turn switches off the car’s reversing light.

The moment the plug and socket are separated the car’s system is back to normal. As Rod says, there is no need to remember to turn anything back on or off, as it is all done automatically.

This is a very simple and effective idea, but the actual wiring procedure is probably not a DIY project. An automotive electrician should have no trouble doing the work once the wire to the car’s stop lights has been identified.

Thanks for sharing this with other readers, Rod.

I tow a single axle 17ft 4in (5.3m) pop-top, ATM 1400kg, with a Toyota Prado. The recommended pressure for the 185R14 light truck tyres is 322kPa (46psi). The experts in the country mention caution about high pressures in the car tyres but don’t say anything about trailers.

Should I be towing my van on these roads? I haven’t as yet. If I do what pressures should I use in the van tyres while on these tyres? Recommended pressure for the Prado is 28psi but I run on 32psi and when towing increase this to 35psi.

Tyre pressures recommended by car manufacturers should be considered as a minimum. That doesn’t mean that you can add another 10psi for good measure but you can do more harm by being a couple of psi under than over.

Generally, tyres pressures are determined by considering the load to be carried and anticipated operating conditions.

As a rule, tyre pressures are increased as the load and/or the speed increases. Conversely you would only lower pressures if you travelled at slower speeds or reduced the load. Two reasons for deflating car tyres are to cope with rough stony roads or to provide better traction when travelling over soft ground. In both cases speeds would be drastically reduced.

As far as trailers are concerned, determining the correct pressure is not as easy. In an ideal world the pressure stated on a trailer plate would be correct for normal operating conditions when the trailer is loaded to its ATM.

Unfortunately some caravan manufacturers look at the maximum pressures stated on the tyre sidewall and transfer this to the trailer data plate. This usually results in the tyres being over inflated. I have also seen figures that relate to the empty weight of the trailer.

Your van will handle unsealed roads as long as you drive to the conditions. In other words, the rougher it is the slower you go. However, long distances on corrugations are not recommended with a standard caravan or pop-top.

The problem with roads like the ones you mentioned is that they can be smooth or very rough, depending on weather conditions and time of the year.

The other thing you need to consider is that the Prado will cope with rough road surface much better than the van. So if the speed feels right for the tow vehicle, it may not be right for the trailer.

Before deciding whether to travel along a particular road or track, check with the road authorities - and if you decide to give it a go, reduce the speed.

I would only reduce the van’s tyre pressures if the surface was rough and I was moving very slowly. But remember, what comes out has to go back in so you’ll need an air-compressor if you are considering letting out air.

A good quality compressor is recommended as some of the cheaper ones can quickly overheat.

While the majority of members belong to their State’s motoring organisation, the type of assistance available depends on your location. There can also be a limit on the weight of the caravan that is recovered.

What organisation, insurance company or similar, will recover your van if it breaks down without costing you the earth? Your advice will be greatly appreciated.

A. Not an easy one to answer, Harold. No doubt you have heard the saying, “you don’t know how good an insurance company is until you make a claim”.

It is somewhat the same with breakdowns. A few organisations promise to help you if you break down but when it comes to the crunch, how well do they do? There are also people who rely on 1800 numbers, take out an extension on the service provided by their motoring organisation or place their trust in a mobile phone.

The bottom line is that if you can’t contact anyone, all the insurance and protection in the world is not going to help. When shopping around for breakdown protection, work out a worst possible scenario and find out what response you can expect if this occurred.

Obviously help is generally not far away if you break down within contact range of a service provider. But what if you are not? A couple of years ago there was an organisation that offered Australia-wide breakdown assistance for caravanners.

I asked what I could expect in the way of help if my caravan broke down halfway between Kununurra and Broome, WA, or Mount Isa and Townsville, Qld, – I never received a reply.

Anyone travelling beyond suburbia should invest in some primary ‘just-in-case’ protection.

This consists of insurance, top membership of a motoring organisation and a UHF radio. As far as insurance is concerned, make sure that you choose a company that offers 24-hour protection, seven days a week, anywhere in Australia – the latter is most important.

I believe that some top motoring organisation membership tables (sounds like health insurance) offer up to 200km towing plus $200 towards the cost of special equipment that may be needed to transport a heavy vehicle or large trailer.

A UHF radio with scanning facilities and an efficient antenna mounting will get you help within most of the ‘tourist’ regions of Australia.

From talking to intrepid travellers, it seems that many caravanners are ‘rescued’ by fellow RVers. This can be by way of having certain spares or know-how, or taking a message to the next town or an area where there may be telephone coverage.

Some advertisements for mobile phones suggest that more than 90 per cent of the Australian population have mobile phone coverage. What is not mentioned is that these live in less than 10 per cent of the country.

Preparation is the most important ingredient in minimising breakdowns. This includes caravan servicing and carrying a few spares like wheel bearings. And, of course, there is safety in numbers.

Although there is never a shortage of travellers along Australia’s sealed roads, no one in their right mind would consider crossing the Simpson by themselves.

The reality is that there are parts of Australia where help is not a phone call away. But that is not an excuse to stay home. Making sure that the car and van are in top condition and having appropriate insurance as backup, means breakdowns are usually taken care of with minor inconvenience.

Rotarians interested in more information about the RVFR can contact Harold Wood, (02) 4983 1431, email: hwwood@bigpond.net.au

As the Viscount is a 16x8 single axle van, I assume that it may be a few years old. It is more than likely that when loaded the van will tip the scales at more than 1200kg. This would indicate that the 1200kg towbar is not up to scratch (I assume by ‘tow hitch’ you mean towbar).

You need to load up the van and visit a weighbridge. Then visit a towing equipment specialist who will point you in the right direction.

I need to ask – why a 9in lift kit? It sounds a little extreme. The LandCruiser will need some special towing equipment to make the 4WD and van match up in regard to towing height.

During a three-week trip of Tasmania, the bottom of the adjustable ballmount hit the ground on many occasions. I’m concerned as to what damage is being done to the weight distribution hitch, the caravan and the car, as well as the ground being hit.

Most problem areas are speed humps and driveways. We have not taken the van offroad as the lack of clearance seems a potential hazard.

The manufacturer said that as there are ADRs controlling tow ball height, nothing could be done.

Options suggested by towing equipment people include raising the coupling with a spacer or fitting a different ballmount that would raise the front of the van. The latter would cause the back of the van to be lower. Any suggestions where we go from here?

A. Allan, yours is not an uncommon problem. Ignoring regulations for a moment, I find it amazing that it is possible to purchase a 4WD and offroad trailer, both designed to provide superior ground clearance, and then finish up with the towing attachment less than 200mm from the ground.

As we have had trailers with offroad capabilities for many years, I’m perplexed as to the reason why someone hasn’t addressed this problem by now.

As you correctly stated, the Australian Design Rules and Australian Standards stipulate a distance of 350mm to 420mm between the ground and the centre of the coupling body.

I’m sure that these rules came into being in the days that offroad trailers were not even thought of.

I have passed your comprehensive letter and pictures on to the RVMAA with the hope that they may lobby to have the rules changed to reflect a real world situation.

You’re right to be concerned about factors other than the actual lack of clearance. Connecting a trailer with a low ball coupling to a 4WD requires a piece of special towing equipment.

This not only lowers the height of the towball, it brings the towball further away from the back of the vehicle.

As a consequence higher forces are transferred to the towbar or hitch receiver as well as the rear portion of the vehicle body, particularly on undulating roads. Needless to say, this is undesirable.

My suggestion is to revert to the standard adjustable ballmount and mount the head in the lowest position. Then calculate the size of the spacer that needs to be fitted under the coupling to allow the trailer to be towed in a level manner.

This will provide some of the much needed clearance, bring the ball closer to the back of the car and reduce the stresses on the towbar and the back of the vehicle.

My concern is that the towball is now located 245mm from the hitch receiver and much lower, where on the AU it was close to the body of the vehicle. Is this a problem or is it a safe setup?

A. Your problem is similar to that of Allan Davis, above. In my book it is undesirable as the ball load from your van exerts additional forces on the hitch receiver and vehicle. The best solution is to have a spacer fitted between the drawbar and the coupling.

This will then allow you to revert to the same setup as used on the AU Falcon. The closer the towball is to the back of the car, the less effect the ball load has on the attitude of the vehicle.

I spoke to the supplier of the lights who said that there must be a fault in the car. Any help would be appreciated.

A. Most manufacturers of quality driving lights also supply wiring kits to eliminate these problems. I’m guessing but it sounds as if there isn’t enough voltage and/or current reaching the lights. This can be due to poor or undersized conductors, bad connections or incorrect wiring of the driving lights in to the car circuit.

Driving lights are usually quite a high wattage and therefore can consume a lot of electrical energy. This means that the conductors or cables have to be a substantial size, both the supply and earth, to allow enough current flow or amperage. Also the conductors have to be as short as possible.

A headlight relay (see diagram) is installed somewhere between the battery and the lights. A cable is then connected between the battery ‘+’ terminal and the relay and the relay and the driving lights.

Normally a wiring diagram is supplied with a relay, which is basically an electrically operated switch. The relay is then activated by a supply from the high beam headlight circuit. A separate driving light on/off switch is added to this circuit.

In this way the driving lights can only be used if the headlights are switched to high beam. When low beam is selected the driving lights will automatically go off. Of course, it is possible to switch off the driving lights if only high beam is needed.

My suggestion is to consult an automotive electrician. Modern car electrical systems are quite complicated and not really in the realm of the DIY enthusiast.